Substiute

y=3x-15

4x+2y=22

You can solve it by replacing the Y in the 2nd equation with the solved Y in the first.

4x + 2 (3x-15) = 22

that should give you ...

4x + 6x - 30 = 22

then combine like terms ...

10x - 30 = 22

now we need to get X alone so add 30 to each side ...

10x = 52

now divide both sides by 10 ...

X = 52/10

both are divisible by 2 ...

X = 26/5

you should be done unless you need Y as well then go back to the first and plug in what you found for X ...

Y = 3 (26:5) - 15

and that should give you Y.

a 2nd method you can make your own answer by making x = 0 ...

Y = 3 (0) - 15

Y = - 15

now put that in the 2nd for Y ...

4x + 2 (-15) = 22 ...

4x-30 = 22

add 30 to both sides ...

4x = 52

divide by 4 ...

X = 13

now take this to the first for x ...

Y = 3 (15) - 15

Y = 30

you can check your work by plugging in the two on top and see if the final is the same ...

30 = 3 (15) - 15

the 2nd way is faster though of course ...

anyway X = 13 Y = 30