Question

how do you solve
x=3y-4
7=y-2x

Answer 1

2 equal signs??

Answer 2

What do x and y represent? It is a bit confusing for me.

Answer 3

You can solve by a method called substitution

Answer 4

substitute x
7 = y-2(3y-4)

Answer 5

x=3y-4
2x=y-7
x=.5(y-7)
plug in one x into the other

Answer 6

x is equal to 3y-4
therefore, in the second equation, write 7=y-2(3y-4)

Answer 7

\[x = -17/5\]
\[y = 1/5\]

Answer 8

Solve this, then plug into the y value into first equaiton to find x

Answer 9

Why is this place filled to the brim? o_0

Answer 10

im so confused what?

Answer 11

Some of you proponents of the substitution method might find this interesting:



It really shines when you have 3 or more variables.

Answer 12

Try substituting the first equation into the second equation.

x= >>> 3y-4 <<<
7=y-2x

So:

7=y-2( >>> 3y-4 <<< )
7=y-2(3y-4)

See how I plugged in the value of x into the second equation?

Answer 13

the lines intersect at \[-17/5 , 1/5\] though

Answer 14

yea i already understand that its the whole solving part i dont get

Answer 15

@alexarchival Show your work so far.

Answer 16

i dont get any of this all i get is how to plug one x in for the other i dont know how to solve

Answer 17

would it be 7=4y+6

Answer 18

7 = y -2(3y-4)

Distribute the -2:

7 = y -6y +8

7 = -5y + 8
-1 = -5y
y = 1/5

Then plug that y into your original equation to get x.

Answer 19

i got -3.4

Answer 20

That's correct. :)

Though, your teacher might want it in fraction form.