Question

A system of equations is shown below.

-3x + 7y = -16
-9x + 5y = 16

Part A: Create an equivalent system of equations by replacing one equation with the sum of that equation and a multiple of the other. Show the steps to do this.

Part B: Show that the equivalent system has the same solution as the original system of equations.

Answer 1

-3x + 7y = -16 . . . (1)
-9x + 5y = 16 . . . .(2)

(1) x 3 => -9x + 21y = -48 . . . (3)
(2) - (3) => -16y = 64 . . . (4)

Required equivalent system of equations is
-9x + 5y = 16
-16y = 64