Question

Solve the simultaneous equations. You must show all your working to find x and y. 1/2x -3y = 9 5x y + y = 28

Answer 1

The right question is:

$\frac{1}{2}x - 3y = 9$

$5x + y = 28$

Answer:

$x = 6$

$y = -2$

Step-by-step explanation:

Given

$\frac{1}{2}x - 3y = 9$

$5x + y = 28$

Required

Solve for x and y

Make y the subject of formula in the second equation

$y = 28 - 5x$

Substitute $y = 28 - 5x$ in the first equation

$\frac{1}{2}x - 3(28 - 5x) = 9$

Open the bracket

$\frac{1}{2}x - 3*28 - 3*- 5x = 9$

$\frac{1}{2}x - 84 + 15x = 9$

Collect Like Terms

$\frac{1}{2}x + 15x = 9+ 84$

$\frac{x}{2} + 15x = 9+ 84$

$\frac{x+30x}{2} = 93$

$\frac{31x}{2} = 93$

Multiply both sides by 2

$2 * \frac{31x}{2} = 93 * 2$

$31x = 186$

Divide both sides by 31

$\frac{31x}{31} = \frac{186}{31}$

$x = \frac{186}{31}$

$x = 6$

Recall that $y = 28 - 5x$

So;

$y = 28 - 5 * 6$

$y = 28 - 30$

$y = -2$

Hence;

$x = 6$ and $y = -2$

Answer 2

The answer to the question is x=6 and y=-2