need help with a math problem?

Question

i'm solving linear systems by substitution equation 1 is 2x+y= -10
equation 2 is 3x-y=0

Answer 1

Use the addtion method so you get 5x=-10 so.... x=-2

Then subsititute it back in 3(-2) -y=0, -y=6 so... y=-6

Answer 2

To solve by substitution, first make y (or x if easier) the subject of one of the equations. For example, by taking 2x away from both sides of equation 1, you get y = -2x - 10

Now put this value of y into equation 2, so wherever you see y, you instead write -2x - 10. That gives 3x - (-2x - 10) = 0. Simplifying this equation will give you a numeric value for x.

Then put this value of x back into your first equation y = ..... Solve that to get a numeric value for y.

Finally, and this is IMPORTANT!, put your values for x and y into both equations to check they balance. If not, go back and see where you went wrong. (The first time I did these equations, I forgot a minus sign - sometimes simple things make the whole thing a mess!)

I won't tell you the answer I got, but hopefully you'll get there on your own - good luck!

Answer 3

Take equation two first.

3x - y = 0 --> y = 3x

For the variable y in equation 1...now subsitute it with 3x

so Eq. 1 now looks like:
2x+3x= -10

Solve for x: x = -2

Then use either equation to solve for y:

Eqn 1:
2(-2) + y = -10
y -4 = -10....y = -6

Answer 4

Add 3x-y + y = 0 +y a y to each side.
3x = y.

2x + 3x = 0
5x = 0
that does not look right. lol. sorry.

Answer 5

solve wither for y
1. 2x+y=-10 or y = -10-2x or y=2x+10
2. 3x-y=0 or -y=-3x or y=3x
Take either and plug the value of y into the equation.

2x + (y=3x) =-10
2x +3x =-10
5x=-10
x=-2
y = 3(-2) = -6