Question

Solve the following systems using the ELIMINATION METHOD. y=4x-5 y=3x+7

Answer 1

$\left\{\begin{array}{ccc}y=4x-5\\y=3x+7&|\text{change the signs}\end{array}\right\\\underline{+\left\{\begin{array}{ccc}y=4x-5\\-y=-3x-7\end{array}\right}\qquad\text{add both sides of the equations}\\.\qquad0=x-12\qquad\text{add 12 to both sides}\\\qquad\boxed{x=12}\\\\\text{Substitute the value of x to the first equation}\\\\y=4(12)-5\\y=48-5\\\boxed{y=43}\\\\Answer:\ x=12\ and\ y=43.$