Question

Which system of equations has an infinite solution? Ay=2x-7 B. x=3y +15 2r+y=5 12 y = 4x-60 D. y = 8 C. 10.x + 8y = -16 -5r = 4y +28 r=8

Answer 1

a. y=2x-7

2x+y=5

y-2x =-7

y+2x =5

add both

0=-2

No solution

b.

x=3y+15

12y=4x-60

x-3y=15

-4x+12y = -60

x=15+3y

Replace x in the second eq

-4(15+3y)+12y=-60

-60-12y+12y=-60

-60=-60

We obtain an obvious result.

The equation has infinite solutions.