Question

Choose a method to solve the following system of equations. Explain why you chose that method.

Solve.

y = 2x + 7

y = -2x - 5

I have been trying to figure it out but idk.

Answer 1

The values for the two equations are x=-3 and y=1

Therefore the solution is (-3,1)

Explanation:

Given equations are
`y=2x+7\hfill (1)`

`y=-2x+5\hfill (2)`

To solve the given equations by Substitution method :

We are using here to solve the given equations by Substitution method because equations (1) and (2) are equivalent ( it has same solution )

Therefore we can equate the two given equations or substitute the y value equation (1) in (2) we get

2x+7=-2x-5

Subtracting with -(2x-5) on both sides we get

2x+7-(-2x-5)=-2x-5-(-2x-5)

2x+7+2x+5=-2x-5+2x+5

4x+12=0 ( adding the like terms )

4x=-12

`x=-(12)/(4)`

Therefore x=-3

Now substitute the value x=-3 in equation (1) we get

y=2(-3)+7

y=-6+7

Therefore y=1

The values are x=-3 and y=1

The solution is (-3,1)