Question

3x+6y=12
-9x+y=21

Answer 1

@Nnesha

Answer 2

you have to make the variable match in both equations. The easiest way to do that would be multiply the first equation by 3

Answer 3

What do you need to do?

Answer 4

don't we change the first equation into y-mx+b

Answer 5

−9x+y+9x=21+9x(Add 9x to both sides)
y=9x+21

Answer 6

it depends on the statement
substitution , elimination/addition , or graphing ?

Answer 7

^thats what i meant to ask.

Answer 8

substitution

Answer 9

aight so continue with this
−9x+y+9x=21+9x(Add 9x to both sides)
y=9x+21

Answer 10

Now that you know what y equals plug it into equation 1
3x+6(9x+21)=12
solve for x

Answer 11

oh I did it the other way lol

Answer 12

\(\color{blue}{\text{Originally Posted by}}\) @jagr2713
don't we change the first equation into y-mx+b
\(\color{blue}{\text{End of Quote}}\)
not necessarily, you don't have to write in slope intercept
you can solve for x too.

Answer 13

ok well what did u get for x?

Answer 14

um -2 so now we plug it into y=9(-2)+21
y=3

Answer 15

Correct