Examples with solutions for Variables and Algebraic Expressions: Only addition and subtraction

Exercise #1

11+5x2x+8= 11+5x-2x+8=

Video Solution

Step-by-Step Solution

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

  • Step 1: Identify the like terms in the expression.
  • Step 2: Combine the constant terms.
  • Step 3: Combine the coefficients of xx.

Now, let's work through each step:
Step 1: The given expression is 11+5x2x+811 + 5x - 2x + 8. There are constants (11 and 8) and terms with xx (5x and -2x).
Step 2: Combine the constants: 11+8=1911 + 8 = 19.
Step 3: Combine the coefficients of xx: 5x2x=3x5x - 2x = 3x.

After simplification, the expression becomes 19+3x19 + 3x.

The correct solution from the multiple-choice options is 19+3x\boxed{19 + 3x}.

Answer

19+3X

Exercise #2

5+0+8x5= 5+0+8x-5=

Video Solution

Step-by-Step Solution

To simplify the expression 5+0+8x55 + 0 + 8x - 5, follow these steps:

  • Step 1: Identify and group like terms. In this case, there are constants (5, 0, -5) and a term with a variable (8x).
  • Step 2: Combine the constants: 5+055 + 0 - 5.
  • Step 3: Calculate: 55=05 - 5 = 0.

Now, our expression simplifies to 0+8x0 + 8x, which is simply 8x8x.

Therefore, the simplified expression is 8x8x.

Answer

8X 8X

Exercise #3

5+89+5x4x= 5+8-9+5x-4x=

Video Solution

Step-by-Step Solution

To solve this problem, we will simplify the expression 5+89+5x4x5+8-9+5x-4x by separately combining the constants and the variable terms.

Step 1: Simplify the constant terms.
5+89=45 + 8 - 9 = 4

Step 2: Simplify the variable terms.
5x4x=x5x - 4x = x

Step 3: Combine the results from steps 1 and 2.
Thus, the simplified expression is 4+x4 + x.

Therefore, the solution to the problem is 4+x4 + x, which corresponds to choice .

Answer

4+X

Exercise #4

x+x= x+x=

Video Solution

Step-by-Step Solution

To solve this algebraic problem, follow these steps:

  • Step 1: Identify the coefficients of the variable x x in the expression x+x x + x . Here, the coefficient for each x x is 1.
  • Step 2: Add the coefficients together. This gives 1+1=2 1 + 1 = 2 .
  • Step 3: Multiply the result by the variable. This results in 2x 2x .

Since the problem is a multiple-choice question, review the available choices to select the correct answer. The expression simplifies to 2x 2x , which corresponds to choice 3: 2x 2x .

Therefore, the solution to the problem is 2x 2x .

Answer

2x 2x

Exercise #5

Are the expressions the same or not?

18x 18x

2+9x 2+9x

Video Solution

Step-by-Step Solution

To determine if the expressions 18x 18x and 2+9x 2 + 9x are equivalent, we'll analyze their structures.

  • 18x 18x is a linear expression with a single term involving the variable x x , and its coefficient is 18.
  • 2+9x 2 + 9x consists of two terms: a constant term 2 2 and a linear term 9x 9x with coefficient 9.

For two expressions to be equivalent, each corresponding term must be equal. Here, the expression 18x 18x has no constant term, whereas 2+9x 2 + 9x has a constant term of 2. Furthermore, the linear term coefficients differ: 189 18 \neq 9 .

Therefore, the expressions 18x 18x and 2+9x 2 + 9x are not the same. They structurally differ and cannot be made equivalent just through similar values of x x .

Therefore, the solution to this problem is: No.

Answer

No

Exercise #6

Are the expressions the same or not?

15x30 15x-30

45155x+15x 45-15-5x+15x

Video Solution

Step-by-Step Solution

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

  • Step 1: Simplify each given expression.
  • Step 2: Compare the simplified expressions to determine if they are equivalent.

Now, let's work through each step:

Step 1: Simplify the expressions

First expression: 15x30 15x - 30

  • The expression is already simplified as it includes one variable term 15x 15x and one constant term 30-30.

Second expression: 45155x+15x 45 - 15 - 5x + 15x

  • Combine the constants: 4515=30 45 - 15 = 30 .
  • Combine the variable terms: 5x+15x=10x-5x + 15x = 10x .
  • The simplified form of the second expression is: 10x+30 10x + 30 .

Step 2: Compare the simplified expressions

After simplification:

The first expression is 15x30 15x - 30 .

The second expression is 10x+30 10x + 30 .

Clearly, these simplified expressions are not the same.

Therefore, the solution to the problem is No.

Answer

No