Solving an Equation by Multiplication/ Division: Opening parentheses

To solve the equation $7y + 10y + 5 = 2(y + 3)$, let's proceed as follows:

• Step 1: Simplify the left side by combining like terms. The expression $7y + 10y$ combines to $17y$, so we have $17y + 5 = 2(y + 3)$.

• Step 2: Expand the right side. Distribute the 2 across the parenthesis: $2(y + 3)$ becomes $2y + 6$. The equation now reads $17y + 5 = 2y + 6$.

• Step 3: Isolate terms involving $y$ on one side. Subtract $2y$ from both sides: $17y - 2y + 5 = 6$, which simplifies to $15y + 5 = 6$.

• Step 4: Isolate $15y$ by subtracting 5 from both sides: $15y = 6 - 5$, which simplifies to $15y = 1$.

• Step 5: Solve for $y$ by dividing both sides by 15: $y = \frac{1}{15}$.

Therefore, the solution to the problem is $\mathbf{y = \frac{1}{15}}$.

To solve the equation $6c + 7 + 4c = 3(c - 1)$, follow these steps:

• Step 1: Combine like terms on the left side of the equation.
  The like terms are $6c$ and $4c$. Combining these gives $10c + 7 = 3(c - 1)$.
• Step 2: Apply the distributive property on the right side of the equation.
  The term $3(c - 1)$ expands to $3c - 3$. Therefore, the equation becomes $10c + 7 = 3c - 3$.
• Step 3: Move all terms involving $c$ to one side and constants to the other.
  Subtract $3c$ from both sides: $10c - 3c + 7 = -3$ which simplifies to $7c + 7 = -3$.
• Step 4: Isolate the term with $c$ by subtracting 7 from both sides of the equation.
  This gives $7c = -3 - 7$ or $7c = -10$.
• Step 5: Solve for $c$.
  Divide both sides by 7: $c = \frac{-10}{7} = -\frac{10}{7}$. This can be converted to a mixed number, giving $-1\frac{3}{7}$.

Therefore, the solution to the equation is $c = -1\frac{3}{7}$. This corresponds to choice 2 in the provided answer choices.

To solve the equation $12y + 3y - 10 + 7(y - 4) = 2y$, follow these detailed steps:

• Step 1: Apply the distributive property to $7(y - 4)$.

This results in:
$12y + 3y - 10 + 7y - 28 = 2y$.

• Step 2: Combine like terms on the left side of the equation.

Combining terms, we have:
$(12y + 3y + 7y) - 10 - 28 = 2y$
$22y - 38 = 2y$.

• Step 3: Move all terms involving $y$ to one side of the equation and constant terms to the other side.

Subtract $2y$ from both sides:
$22y - 2y = 38$
$20y = 38$.

• Step 4: Solve for $y$ by dividing both sides by 20.

$y = \frac{38}{20} = 1.9$.

Therefore, the solution to the equation is $y = 1.9$.

To solve the equation $\frac{1}{3}(x+9) = 4+\frac{2}{3}x$, we will follow these steps:

• Step 1: Clear fractions by multiplying through by the least common denominator.
• Step 2: Simplify the equation to combine like terms.
• Step 3: Solve for $x$.

Let's begin:

Step 1: Multiply every term in the equation by 3 to eliminate fractions:

This simplifies to:

Step 2: Rearrange the equation to get all $x$ terms on one side and constant terms on the other:

Subtract $2x$ from both sides:

Which simplifies to:

Next, subtract 9 from both sides to isolate terms involving $x$:

Step 3: Solve for $x$ by multiplying both sides by -1:

Thus, the solution to the equation is $x = -3$.

To open the parentheses on the left side, we'll use the formula:

$-a\left(b+c\right)=-ab-ac$

$-12a-24=27a$

We'll arrange the equation so that the terms with 'a' are on the right side, and maintain the plus and minus signs during the transfer:

$-24=27a+12a$

Let's group the terms on the right side:

$-24=39a$

Let's divide both sides by 39:

$-\frac{24}{39}=\frac{39a}{39}$

$-\frac{24}{39}=a$

Note that we can reduce the fraction since both numerator and denominator are divisible by 3:

$-\frac{8}{13}=a$

To solve the given linear equation $-\frac{7}{4}(-x) + 2x - 5(x + 3) = -x$, follow these steps:

• Step 1: Distribute the coefficients across the terms within parentheses:
  The term $-\frac{7}{4}(-x)$ becomes $\frac{7}{4}x$ because $-\frac{7}{4} \times -x = \frac{7}{4}x$.
  The term $-5(x + 3)$ can be expanded to $-5x - 15$.
• Step 2: Simplify the equation by combining like terms:
  The equation becomes $\frac{7}{4}x + 2x - 5x - 15 = -x$.
• Step 3: Combine the $x$-terms on the left side:
  Combine: $\frac{7}{4}x + 2x - 5x$.
  Converting all terms to a common denominator, $2x = \frac{8}{4}x$ and $-5x = \frac{-20}{4}x$. Thus,
  $\frac{7}{4}x + \frac{8}{4}x - \frac{20}{4}x = \frac{-5}{4}x$.
• Step 4: The equation simplifies to:
  $\frac{-5}{4}x - 15 = -x$.
• Step 5: Isolate the $x$ terms onto one side:
  Add $x$ to both sides, treating $-x$ as $\frac{-4}{4}x$:
  $\frac{-5}{4}x + x - 15 = 0$, which simplifies to $\frac{-1}{4}x - 15 = 0$.
• Step 6: Isolate $x$:
  Add $15$ to both sides:
  $\frac{-1}{4}x = 15$.
• Step 7: Solve for $x$:
  Multiply both sides by $-4$ to isolate $x$:
  $x = 15 \times -4$.
  Thus, $x = -60$.

Therefore, the solution to the equation is $x = -60$.

To solve this problem, we'll follow these steps:

• Step 1: Distribute on the right-hand side
• Step 2: Combine like terms on the left-hand side
• Step 3: Isolate the variable $x$
• Step 4: Solve for $x$

Now, let's work through each step:

Step 1: Distribute on the right-hand side of the equation:

$2x + 45 - \frac{1}{3}x = 5(x + 7) \quad \Rightarrow \quad 2x + 45 - \frac{1}{3}x = 5x + 35$

Step 2: Combine like terms on the left-hand side:

Combine $2x$ and $-\frac{1}{3}x$ on the left:

$2x - \frac{1}{3}x = \frac{6}{3}x - \frac{1}{3}x = \frac{5}{3}x$

The equation becomes:

$\frac{5}{3}x + 45 = 5x + 35$

Step 3: Move all terms with $x$ to one side and constants to the other:

$\frac{5}{3}x - 5x = 35 - 45$

Step 4: Simplify and solve for $x$:

$\frac{5}{3}x - \frac{15}{3}x = -10$ $-\frac{10}{3}x = -10$

Step 5: Solve for $x$ by dividing both sides by $-\frac{10}{3}$:

$x = \frac{-10}{-\frac{10}{3}} = 3$

Therefore, the solution to the problem is $x = 3$.

To solve this equation, we'll follow these steps:

• Step 1: Expand and simplify the right-hand side.
• Step 2: Set the equation to zero by moving all terms to one side.
• Step 3: Simplify to obtain a standard quadratic equation.
• Step 4: Use the quadratic formula to find the possible solutions for $x$.

Now, let's work through each step:

Step 1:
Expand the right-hand side:
$(-x + 7)(4x - 9) = -x(4x) - x(-9) + 7(4x) - 7(9)$
= $-4x^2 + 9x + 28x - 63$
Considering both sides: $-4(x^2 + 5) = -4x^2 + 9x + 28x - 63 + 5$.

Step 2:
Simplify further by calculating:
$-4x^2 - 20 = -4x^2 + 37x - 58$.

Step 3:
Move all terms to one side to achieve zero on the right-hand side:
$-4x^2 - 20 + 4x^2 - 37x + 58 = 0$
Simplifying, we get: $37x + 38 = 0$.

Step 4:
Since the $x^2$ terms cancel, it's actually a linear equation:
$37x = -38$.
Solving for $x$, we divide both sides by 37:
$x = \frac{-38}{37} = -1\frac{1}{37}$.

Therefore, the solution to the problem is $x = 1\frac{1}{37}$.