Question

I need 4 answers done, I need you to tell me how to do it, and show your work for the answers!

Answer 1

Answer:

13) $x=-3,y=4$

14) $x=7, y=12$

15) $x=-1,y=3$

16)$x=-3,y=4$

Step-by-step explanation:

13)

$y=9x+31\\6x+4y=-2$

Sub in equation 1 into equation 2.

$6x+4(9x+31)=-2$

Expand the bracket.

$6x+36x+124=-2$

Rearrange.

$42x=-126\\x=-3$

Solve for y.

$y=9(-3)+31\\y=-27+31\\y=4$

14) (Following exactly the same steps)

$y=-2x+26\\-5x+2y=-11$

$-5x+2(-2x+26)=-11\\-5x-4x+52=-11\\-9x=-63\\x=7$

$-5(7)+2y=-11\\2y=24\\y=12$

15) (Following exactly the same steps again.)

$y=2x+5\\8x+3y=1$

$8x+3(2x+5)=1\\8x+6x+15=1\\14x=-14\\x=-1$

$8(-1)+3y=1\\-8+3y=1\\3y=9\\y=3$

16) (Still no variation on how the questions are asked, exact same method)

$3x+2y=-2\\y=9x+31$

$3x+2(9x+31)=-1\\3x+18x+62=-1\\21x=-63\\x=-3$

$y=9(-3)+31\\y=-27+31\\y=4$