Question

How do I solve using the substitution method?
y = 2x - 5
3y - x = 5

Answer 1

Since y = 2x - 5, you can put substitute that into the second equation:

3y - x = 5
3(2x-5) - x = 5

just solve for x from here...

Answer 2

just sub 2x - 5 in for y in the second equation, then solve for x.

Answer 3

3(3x-5) - x = 5
9x - 15 - x = 5
8x - 15 = 5
8x = 20
/8 /8
x = 2.5

Answer 4

I made a mistake

Answer 5

no.....2x - 5 not 3x - 5.....

Answer 6

3(2x-5) - x = 5
6x - 15 - x = 5
5x - 15 = 5
5x = 20
x = 4 ?

Answer 7

you got it James....now you can sub 4 in for x in either of the original equations and solve for y.

Answer 8

omg. Thanks a lot!

Answer 9

your welcome....do you know how to check your answer to see if it is correct ?

Answer 10

y = 2 * 4 - 5
y = 3

Answer 11

(4,3)

Answer 12

Let me check because I haven't even done the problem yet....
3(2x - 5) - x = 5
6x - 15 - x = 5
5x = 20
x = 4

y = 2x - 5
y = 2(4) - 5
y = 8 - 5
y = 3

check...
3y - x = 5
3(3) - 4 = 5
9 - 4 = 5
5 = 5 (correct)

or/and check with the other equation...
y = 2x - 5
3 = 2(4) - 5
3 = 8 - 5
3 = 3 (correct)

ANSWER : (4,3)

You got it James.....way to go :)

Answer 13

seriously thanks for the help!

Answer 14

not a problem...thats what I am here for :)