Question

Solve the following system of equations with the substitution method:

y=3/5x-15
y=-3/4x+12

Answer 1

x = 20, y = -3

Explanation:

Set both equations equal to each other

`\displaystyle y=(3)/(5)x-15\\\\y=-(3)/(4)x+12\\\\\\\\(3)/(5)x-15=-(3)/(4)x+12\\\\(12)/(20)x-15=-(15)/(20)x+12\\\\(27)/(20)x-15=12\\\\(27)/(20)x=27\\\\x=20\\\\y=(3)/(5)x-15\\\\y=(3)/(5)(20)-15\\\\y=(60)/(5)-15\\\\y=12-15\\\\y=-3`