Solve Simultaneous Equations: 4x - 7/y = -3 and 5x + 2/y = 7

Question

4x7y=3 4x-\frac{7}{y}=-3

5x+2y=7 5x+\frac{2}{y}=7

Video Solution

Step-by-Step Solution

To solve the system of equations, we will apply the substitution method:

We start with the given equations:

4x7y=3 4x - \frac{7}{y} = -3 (Equation 1)

5x+2y=7 5x + \frac{2}{y} = 7 (Equation 2)

Let's start by solving Equation 1 for 1y \frac{1}{y} :

4x7y=3 4x - \frac{7}{y} = -3

Rearrange to isolate 1y \frac{1}{y} :

7y=34x -\frac{7}{y} = -3 - 4x

Multiply through by -1 to simplify:

7y=4x+3 \frac{7}{y} = 4x + 3

1y=4x+37 \frac{1}{y} = \frac{4x + 3}{7} (Equation 3)

Now, substitute Equation 3 into Equation 2:

5x+2y=7 5x + \frac{2}{y} = 7

Replace 1y \frac{1}{y} from Equation 3:

5x+2(4x+37)=7 5x + 2 \left(\frac{4x + 3}{7}\right) = 7

Multiply both sides of the equation by 7 to eliminate the fraction:

35x+2(4x+3)=49 35x + 2(4x + 3) = 49

Expand and simplify:

35x+8x+6=49 35x + 8x + 6 = 49

43x+6=49 43x + 6 = 49

Subtract 6 from both sides:

43x=43 43x = 43

Divide by 43:

x=1 x = 1

Substitute x=1 x = 1 back into Equation 3 to solve for y y :

1y=4(1)+37 \frac{1}{y} = \frac{4(1) + 3}{7}

1y=4+37 \frac{1}{y} = \frac{4 + 3}{7}

1y=77 \frac{1}{y} = \frac{7}{7}

1y=1 \frac{1}{y} = 1

Therefore, y=1 y = 1

The solution to the system of equations is x=1,y=1 x = 1, y = 1 .

Answer

x=1,y=1 x=1,y=1