Question

Solve using substitution.
5x + 12y = 146
x - 12y = -158

Answer 1

First find the value of x in terms of y.

\(\sf x+158=12y\\ \Rightarrow x=12y-158\)

Answer 2

Now substitute this value of x in other equation.

Answer 3

5(12y-158)+ 12y = 146
60y-790+12y=146
72y-790=146

Answer 4

is that right so far?

Answer 5

yes

Answer 6

72y-790=146
add 790 to both sides
72y=-644
this is the part i get stuck on

Answer 7

when i divide I get a fraction =/

Answer 8

\(\sf 72y=146+790 \\ \huge y = \frac{146+790}{72}\)

Answer 9

oh whoops 936/72=13 yay!! i got :D

Answer 10

so y=13

Answer 11

wait now im confused where would i sub?

Answer 12

:(

Answer 13

Yes, y =13. Now substitute this value of y in any of the original equations and calculate the value of x

Answer 14

x=12y−158
x=12(13)-158
x=156-158
x=-2?

Answer 15

Correct :)

Answer 16

yay!