Question

Pleasee help the method is either substitution, equal values, or elimination and PLEASE explain step by step

y = 0.25x + 3
x = -4y + 8

Answer 1

x = -2 and y = 2.5

Explanation:

using elimination method:

y = 0.25x + 3 call this equation '1'

x = -4y + 8

bring 4y on its own

4y = -x + 8 call this equation '2'

multiply '1' by 4:

4y = x + 12 call this equation '3'

add '2' and '3'

8y = (-x + x) + 20

8y = 20

y = 20/8 = 2.5.

go back to '1'

we have y = 0.25x + 3

2.5 = 0.25x + 3

subtract 3 from both sides

2.5 - 3 = 0.25x

-0.5 = 0.25x

multiply both sides by 4

-2 = x

x = -2

now put both y =2.5 and x = -2 into '2' to see if all is fine

4y = -x + 8

4(2.5) = -(-2) + 8

10 = +2 + 8

10 = 10

so x = -2 and y = 2.5