Question

Use the substitution method to solve the system of equation.choose the correct ordered pair.

2y+4x=18
2y-3x=4

Answer 1

`\left\{\begin{array}{ccc}2y+4x=18\\2y-3x=4&\text{add 3x to both sides}\end{array}\right\\\\\left\{\begin{array}{ccc}2y+4x=18&(**)\\2y=3x+4&(*)\end{array}\right\\\\\text{Substitute}\ (*)\ \text{to}\ (**):\\\\3x+4+4x=18\qquad\text{subtract 4 from both sides}\\7x=14\qquad\text{divide both sides by 7}\\\boxed{x=2}\\\\\text{Put the value of x to the first equation:}\\\\2y+4(2)=18\\2y+8=18\qquad\text{subtract 8 from both sides}\\2y=10\qquad\text{divide both sides by 2}\\\boxed{y=5}\\\\Answer:\ \boxed{x=2\ and\ y=5}`