Question

Solve the system by substitution. Check your solution.

0.5 x + 0.25 y = 36. y + 18 = 16 x.
a.
(36, 72)
c.
(49, 81)
b.
(9, 126)
d.
(21, 9)

Answer 1

(9,126)

Explanation:

Make sure x and y are on the same side

`0.5x+0.25y=36\\16x-1y=18`

Eliminate y by multiplying the first equation by 4 then adding both equations together

`2x+1y=144\\16x-1y=18\\18x=162\\x=9`

Plug the x value (9) into one of the equations

`16(9)-1y=18`

Solve

`16(9)-1y=18\\144-1y=18\\144=18+1y\\126=y`

x=9, y=126

(9,126)