should you choose substitution or elimination to save this system. Explain

Question

3x+4y=-9

9x+2y=3

elimination ot substitution

solution

Y=-3 X=1

Answer 1

multiply the 2nd equation by 2 and subtract the 1st equation from that to eliminate y

18x+4y =6

3x +4y=-9

15x = 15

x = 1

then substitute x=1 into either original equation to solve for y

or multiply the 1st equation by 3 and subtract the 2nd equation from that to eliminate x

9x +12y =-27

9x +2y =3

10y =-30

y =-3

then subsitute y=-3 into either original equation to solve for x