Question

How would I find. The solution of the system? Use elimination.
3x-4y=9-3x+2y=9

Answer 1

3x - 4y = 9
-3x + 2y = 9
are these your 2 equations ?

Answer 2

Yes

Answer 3

then add them and what do you get ?

Answer 4

keep in mind, a -3 and a + 3 cancel....so your x's will be eliminated

Answer 5

After the png, Substitute (4y+9) for x in −3x+2y=9:

Answer 6

the question specifies elimination, not substitution

Answer 7

Yes but it could potentially be solved either way.

Answer 8

true ^^

Answer 9

Substitution would be harder but it would get the job done.

Answer 10

And after you do the steps after that, Substitute (
−18
5
) for y in x=4y+9:

Answer 11

Those 2 will be your answers.

Answer 12

A. (3,9) b. (-27, -9) c (-3,-6) d. (-9,-9) these are answers

Answer 13

3x - 4y = 9
-3x + 2y = 9
-------------add
-2y = 18
y = 18/-2
y = -9

now sub -9 in for y in either of your original equations to find x
3x - 4y = 9
3x - 4(-9) = 9
3x + 36 = 9
3x = 9 - 36
3x = - 27
x = -27/3
x = - 9

you can then check your answers by subbing in what you got for x and y
-3x + 2y = 9
-3(-9) + 2(-9) = 9
27 - 18 = 9
9 = 9 (correct)

so your solution is : (-9,-9)