Question

use the subtitution method to solve.
x^2 + 2y = 9
x - y + 3 = 0
can someone help me?

Answer 1

from equation (2):
y=x+3 -> (3)
substitute for y with x+3, you get:
\[x^2+2(x+3)=9 \implies x^2+2x-3=0\]
factorize it to get:
\[(x+3)(x-1)=0 \implies x=-3, x=1\]
substitute for each value of x in equation 3\[x=-3 \implies y=-3+3=0\]
\[x=1 \implies y=1+3=4\]

Answer 2

therefore the problem has two solutions:
\[(x,y)=(-3,0) , (x,y)=(1,4)\]

Answer 3

Ok I get it. My answer was really close to that. Thank you!

Answer 4

you're welcome :).. feel free to fan me ;)