Question

Which of the following points solves the system shown below?

y = 5x -9
y = -2x + 12
Choose from the following...
1) (1, -4) 2) (2,8) 3) (3,6) 4) (-3, 18)

Answer 1

(3,6)

Explanation:

Collect like terms

y -5x = -9

y + 2x = 12

Using elimination method

Subtract equation 2 from equation 1

y - 5x = -9

y + 2x = 12

---------------

0. -7x = -21

Divide both sides by -7

-7x = -21

---- -----

-7 -7

x = 3

Substitute x=3 into equation 1

y = 5(3) - 9

y = 15 - 9

y = 6

Solution is (x,y) = (3,6)