Question

13x=-21-6y and -8x=36+6y

Answer 1

Answer:

$x=3\\y=-10$

Step-by-step explanation:

$13x=-21-6y\\-8x=36+6y$

Let's take one of the equations and solve for x. I'll take the first one.

$13x=-21-6y$

Divide by 13.

$x=\frac{-21-6y}{13}$

Now replace x in the second equation.

$-8x=36+6y\\-8(\frac{-21-6y}{13} )=36+6y$

Distribute -8

$\frac{168+48y}{13}=36+6y$

Break down the fraction.

$\frac{168}{13}+\frac{48}{13}y=36+6y$

Subtract $\frac{168}{13}$

$\frac{48}{13}y=36+6y-\frac{168}{13}$

Subtract 6y

$\frac{48}{13}y-6y=36-\frac{168}{13}$

Combine like terms;

$\frac{48-13*6}{13}y=\frac{36*13-168}{13}$

Solve;

$\frac{48-78}{13}y=\frac{468-168}{13}$

Keep solving;

$\frac{-30}{13}y=\frac{300}{13}$

Multiply by the negative reciprocal of the fraction next to y.

$(-\frac{13}{30} )\frac{-30}{13}y=\frac{300}{13}(-\frac{13}{30} )$

On the right side; 13 and 13 become 1. 300/30 = 30/3 = 10

$y=-10$

After having found y, replace it in any of the equations to find x.

$13x=-21-6y\\13x=-21-6(-10)\\13x=-21+60\\13x=39\\x=\frac{39}{13}\\ x=3$

Answer 2

Answer:

x=3

y=-10

Step-by-step explanation:

13x=-21-6y...............(1)

-8x=36+6y................(11)

Add (11) to (1)

5x=15-6y+6y

5x=15

Divide both sides by 5

5x/5=15/5

x=3

Substitute x=3 in 13x=-21-6y

13(3)=-21-6y

39=-21-6y

Collect like terms

39+21=-6y

60=-6y

Divide both sides by -6

60/-6=-6y/-6

-10=y

y=-10