Question

hey guys i need your help i don't really know how to solve this 3x-y=5 and 2x+y=-10 in substitution way.tnx

Answer 1

-y = 5 - 3x

y = -5 + 3x or y= 3x-5

substituting it to the 2nd equation, we have:

2x + (3x - 5) = -10

5x - 5 = -10

5x = -10 +5

5x = -5

x = -1

y = 3x - 5

y = 3(-1) - 5

y = -3 - 5

y = -8

Answer 2

thanks you so much

Answer 3

No prob :))

Answer 4

substitution means to make one equation equal one of the variables in the second then plug it in so:

3x-y=5 lets solve for y
3x-5=y

plug that into the second equation.


2x+y=-10
2x+(3x-5)=-10
5x-5=10
5x=-5
x=-1

then plug that into either of the origonal equations to find y

2x+y=-10
2(-1)+y=-10
-2+y=-10
y=-8

and i realized that someone already finished this but i hope it still helps

Answer 5

@jdhyde, haha. XD

Answer 6

ya im not all that fast at typing but i know my math

Answer 7

yeah really big help thank you for spending your time with me.

Answer 8

Good for you. :))