What is the point that passes through -7x plus y equals -20 and 9x-3y equals 36?

Answer 1

you begin with -7x+y=-20 and 9x-3y=36

7x-7x+y=-20+7x (add 7x to both sides)

y=7x-20 (simplify)

9x-9x-3y=36-9x (subtract 9x from both sides)

-3y/-3=36/-3-9x/-3 (divide both sides by -3)

y=3x-12 (simplify)

y=y so 7x-20=3x-12

7x+20-20=3x-12+20 (add 20 to both sides)

7x=3x+8 (simplify)

7x-3x=3x-3x+8 (add 3x to both sides)

4x=8 (simplify)

4x/4=8/4 (divide by 4 on both sides)

x=2 (simplify)

9(2)-3y=36 (plug in 2 for x)

18-3y=36 (simplify)

18-18-3y=36-18 (subtract 18 from both sides)

-3y=18 (simplify)

-3y/-3=18/-3 (divide by -3 on both sides)

y=-6 (simplify)

the point is 2,-6 (x,y)