X+y=120

5.25x+3.0y=517.2

I will try to solve your system of equations.

x+y = 120; 5.25x + 3y = 517.2

Step: Solve x+y = 120 for x:

x+y + - y = 120 + - y (Add - y to both sides) x = - y + 120

Step: Substitute - y + 120 forxin 5.25x + 3y = 517.2:

5.25x + 3y = 517.2 5.25 (-y + 120) + 3y = 517.2 - 2.25y + 630 = 517.2 (Simplify both sides of the equation) - 2.25y + 630 + - 630 = 517.2 + - 630 (Add - 630 to both sides) - 2.25y = - 112.8 - 2.25y - 2.25 = - 112.8 - 2.25 (Divide both sides by - 2.25) y=50.133333

Step: Substitute50.133333foryin x = - y + 120:

x = - y + 120 x = - 50.133333 + 120 x=69.866667 (Simplify both sides of the equation)

Answer:

x = 69.866667 and y = 50.133333