40.8k views
20 votes
PLEASE HELP ASAP!!

Solve the system of linear equations by elimination.
9x+2y=39
6x+13y=-9
( __,___ )

2 Answers

9 votes

Answer:

5,-3

Explanation:

First, you need one of the numbers in front of the variables to be the same in each equation so that you can cancel them out. so find the lowest number that they both can multiply to. The lowest number that they can both multiply to is 18. So this is what the first equation would look like,

2x(9x+2y=39)

You need to multiply all the numbers in that equation by two

Then multiply the second equation by -3

-3x(6x+13= -9)

So the equations would look like this:

18x+4y=78

-18x-39y=27

________________

Then you need to add them together so you would get

0x (-18+18 cancels it out) -35y=105

Then divide each side by -35 and you'll get

y= -3

Last step,

9x+ 2(-3)= 39

(replace the y with -3 since that was our answer)

add six to both sides and then divide each side by 9 and you'll get

9x-6=39

+6 +6

_________

9x=45

________

9 9

x=5

(5, -3)

Sorry that i'm a year late btw

User Rene Saarsoo
by
4.9k points
5 votes

Answer:

x = 5

y = -3

Explanation:


9x + 2y = 39 \: \: \: \: \: \: \: \: \: (2)\\ 6x + 13y = - 9 \: \: \: \: \: \: \: \: \: \: ( - 3) \\ \\ 18x + 4y = 78 \\ - 18x - 39y = 27 \\ \\ - 35y = 105 \\ y = (105)/( - 35) \\ y = - 3 \\ \\ 9x + 2y = 39 \\ 9x + 2( - 3) = 39 \\ 9x - 6 = 39 \\ 9x = 39 + 6\\ x = (45)/(9) \\ x = 5

User GuidoS
by
4.9k points
Welcome to QAmmunity.org, where you can ask questions and receive answers from other members of our community.