For the first one, you were solving everything correctly, but at -2x=2, you divided incorrectly. You have it equal to -2. But, -2÷2 = -1. So, x=-1
Your answer is correct for number 2, 3, 4, and 5
But, once you find one variable, plug that number back into an equation to find the other equation.
So, for example, for the number 2, you solved the equations to find that x=2. Now, take x=2 and plug 2 in for x in one of the equations to find what y equals.
So...
3(2)-1=y
6-1=y
y=7
So, once you have solved for both x and y for all of the equations, then you have fully completed the problem.
For number 6, you need to isolate one of the variables in one of the equations. So, to do that... let's solve for y
y+2x=11
Perform the opposite operation and subtract 2x from both sides of the equation
2x will cross out on the left
2x - 2x = 0
Remeber to subtract 2x on the right side of the equation as well
y=-2x+11
Now you can plug this equation into 4x + 4y =42 and solve for x
I hope that helps, let me think about 7 and 8 and I'll get back to you. Leave a comment if you have any questions :)
