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?
-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
