Question

For the following system, if you isolated x in the second equation to use the Substitution Method, what expression would you substitute into the first equation?

3x + y = 8
−x − 2y = −10

Answer 1

the first equation would the most accurate; or 3x+y=8

Answer 2

isolate x in 2nd equation...

-x - 2y = -10 ....add 2y to both sides
-x = 2y - 10 ...multiply by -1 to make x positive
x = -2y + 10 <== u would sub in -2y + 10 in for x in the 1st equation