114k views
1 vote
Help me please I don’t understand this thing

X+2y=10
2x-y=5

User Panosru
by
8.0k points

1 Answer

1 vote

Answer: (4,3)

Rearrange the first equation so that only y is on the left side.

x + 2y = 10

Subtract x on both sides.

2y = -x + 10

Divide by 2 on both sides, to get y by itself.

y = -0.5x + 5

Rearrange the second equation so that only y is on the left side.

2x - y = 5

Subtract 2x on both sides.

-y = -2x +5

To get rid of the negative sign on front of y, divide both sides by -1.

y = 2x - 5

Now you have: y = -0.5x + 5 and y = 2x - 5. Because both equations are equal to y, you can set both of these two equations equal to each other in order to solve for x.

-0.5 x + 5 = 2x - 5

Add 0.5x to both sides.

5 = 2.5x -5

Add 5 to both sides.

10 = 2.5x

Divide both sides by 2.5.

x = 4

Now that you have the value of x (x=4), use one of the original equations and substitute the x for 4.

x + 2y = 10.

(4) + 2y = 10

Subtract 4 on both sides.

2y = 6

Divide by 3 on both sides.

y = 3

x=4 and y=3 can also be written in (x,y) form as (4,3).

User Dan Vega
by
7.3k points