Question

Please Help me with these 2 questions I have been trying to figure them out for over 30 minutes !
1.Use the substitution method to solve the following system of equations.

6x + 3y = -7
12x + y = 6




2.If you were to use the substitution method to solve the following system, choose the new equation after the expression equivalent to y from the second equation is substituted into the first equation.

2x - 5y = -3
6x - 3y = -3
these are my options
2(2x + 1) - 5y = -3
2(-2x - 1) - 5y = -3
2x - 5(2x + 1) = -3
2x - 5(-2x - 1) = -3

Thank you in advance!

Answer 1

\[12x + y = 6 \iff y=6-12x\] is a start

Answer 2

Take that (6-12x) and replace y in your first equation with it :)

Answer 3

then
\[6x + 3y = -7\] becomes
\[6x+3(6-12x)=-7\]

Answer 4

Then use the distributive property a(b+c)=ab+ac on 3(6-12x)

Answer 5

to get
\[6x+18-36x=-7\]

Answer 6

Collect like terms to get...

Answer 7

\[-30x+18=-7\]

Answer 8

Now we want to isolate x...

Answer 9

\[-30x=-7-18=-25\]

Answer 10

The last thing to undo is that multiplication by -30

Answer 11

\[x=-25\div -30=\frac{5}{6}\]

Answer 12

Then you take that value you found for x and plug it into one of the equations given to find y

Answer 13

or as satellite had said y=6-12x

Answer 14

oThis is already solved for y all you have to do is replace x with 5/6 and simplify

Answer 15

\[12x + y = 6 \]
\[y=6-12(\frac{5}{6})\]

Answer 16

\[y=6-2\times 5=6-10=-4\]

Answer 17

And that is how you use the order of operations :)

Answer 18

To simplify the value for y

Answer 19

myininaya not only is the coolest person in open study, she also has the best hair do

Answer 20

Thank you guys soooooooooooooooooooooooooooooooooooooooooooooooooooooooooo much ! This helped me big time and showed me exactly how to go about solving that! I really appreciate it!

Answer 21

yw

Answer 22

@satellite73 did most of the work. He is a brilliant teacher.

Answer 23

gotta run, honeymooners is on
no no, you did all the work, i did the donkey part (mechanics)