y= -x+8 and y=x

Question

what is y=-x+8 and y=x

 

Answer 1

Hi, Shay.

This problem looks like a good candidate for using substitution to solve it.

y = -x  + 8
y = x

We can substitute x (from the second equation) in place of y (in the first equation):

x = -x  +  8

Now solve the new equation by getting the variable term on only one side:

  x  =   -x   + 8
+x      +x                                                                   .
2x   =     8

Now divide by 2 on both sides...

2x  =  8 
 2       2

x = 4

This problem is almost done.  You need to determine the value of y too.  Since y = x, they have the same value.  Does your teacher want the answer in ordered pair form (x, y)?   If so, my answer is (4, 4).