Question

2. A system of equations is shown below.
{5x+ 9y=-54
{2x+ y=20

a.) Find the solution to the system of equations using either substitution or the linear combination method. Show all your work.

Answer 1

2x + y = 20 --- is that what this equation is ??

Answer 2

yes, it is all in one bracket but i didn't know how to do that

Answer 3

2x + y = 20
y = -2x + 20
understand so far ?

Answer 4

now sub -2x + 20 in for y in the other equation
5x + 9y = -54
5x + 9(-2x + 20) = -54 -- distribute through the parenthesis
5x - 18x + 180 = -54 -- combine like terms
-13x + 180 = -54 -- subtract 180 from both sides
-13x = -54 - 180
-13x = - 234
x = 18

now sub 18 in for x in either of the equations
2x + y = 20
2(18) + y = 20
36 + y = 20
y = -36 + 20
y = -16

check..
2x + y = 20
2(18) -16 = 20
36 - 16 = 20
20 = 20 (correct)

solution is : x = 18 and y = -16
any questions ?

Answer 5

no ma'am thank you so much again! i need help with one more, can you help? c:

Answer 6

I can try