Question

Y=x
y=2x+9
how do I do it

Answer 1

Hi there!

To solve this problem, we need to substitute. Since y = x, then x = 2x + 9.

We can simplify this.

x = 2x + 9
-x = 9
x = -9

And since y=x...

y = -9

Hope this helps!

Answer 2

y=x;y=2x+9Step: Solve y=xfor y:Step: Substitute x for y in y=2x+9:y=2x+9x=2x+9x+−2x=2x+9+−2x(Add -2x to both sides)−x=9−x−1=9−1(Divide both sides by -1)x=−9Step: Substitute −9 for x in y=x:y=xy=−9

Answer:x=−9 and y=−9