Question

Solve the system of linear equations below.

6x + 3y = 33
4x + y = 15
Select one of the options below as your answer:



A.
x = 2, y = 7




B.
x = -13, y = 7




C.

x = - 2

3 , y = 12 2

3




D.
x = 5, y = 1

Answer 1

are you familiar with the elimination method ?

Answer 2

somewhat

Answer 3

multiply the 2nd equation by -3

Answer 4

or...would you rather do substitution ?

Answer 5

substitution is far easier for me

Answer 6

ok....look at the 2nd equation...can you isolate y ?

Answer 7

BY adding 4x to the opposite side?

Answer 8

subtracting*

Answer 9

no...subtract 4x from both sides

Answer 10

so y=15-4x

Answer 11

correct....now sub 15 - 4x in for y in the 1st equation

Answer 12

6x+3(15-4x)=33?

Answer 13

yes......now distribute the 3 through the parenthesis

Answer 14

6x+45-12x=33. Now C.L.T right?

Answer 15

correct....combine like terms

Answer 16

-6x+45=33

Answer 17

correct....now subtract 45 from both sides...or add 6x to both sides...whichever you want to do

Answer 18

but if you add 6x, you also have to subtract 33 from both sides

Answer 19

-6x=-12 now divide by negative 6?

Answer 20

correct....now divide both sides by 6 keeping in mind dividing by 2 negatives gives you a positive

Answer 21

so that gives me x=2 now I put that in for x on one of the equations right

Answer 22

correct

Answer 23

and theen solve the same way

Answer 24

yes

Answer 25

you can then check your answers by subbing both x and y into either of the equations and if they come out equal, you have found the correct answers

Answer 26

ok I put x into the first equation listed and then have gotten to 12=33-3y. What now?

Answer 27

6(2) + 3y = 33
12 + 3y = 33
how did you get that ?
from here you subtract 12 from both sides

Answer 28

ohhhh I subtracted 3y first

Answer 29

you are trying to get 3y on one side and everything else on the other side

Answer 30

you got it now...good job