Up Your Score SAT, 2018-2019 Edition The Underground Guide to Outsmarting The Test

10 x    +   16y =   22

Subtract    the bottom  equation    from    the top one:

Then    take    either  equation    and plug    in  –8  for y   and solve   for x:

SECOND METHOD: SUBSTITUTION

Pro Tip:    If  you are graphing    these   equations   on  a

graphing    calculator, their   solution    is  the same    as  the

point   of  intersection.

Substitution is an easier method for solving a system of equations in cases when
one of the variables isn’t multiplied by a number. For example:

3 x +   2y  =   6

        –2x +   y   =   10

Notice that the y in the second equation is all by itself. This is a big fat clue
that substitution is the way to go. Start by focusing on that second equation.
Isolate y in terms of x by adding 2x to both sides, giving you:

y   =   2x  +   10

Next, you want to substitute that expression for y into the first equation of the
system. Then solve for x: