Which pair shows equivalent expressions? 2x+10=-2(x-5)
-2(x+5)=2x-10
-2x-10=-(x+5)
-(2x-5)=-2x-10

Solve the two equations simultaneously:
3x+5y=100
x+y=24
Multiply the 2nd equation by 3 so you can have the same coefficient of one of the variables (in this case, x)
3x+5y=100
3x+3y=72
Minus the second equation from the first to give you:
2y=28
Divide by 2 on both sides to give you y=14
Substitute 14 for y into one of the equations:
x+y=24
x=10
Remember that 3x+5y=100
So the test contains 10 3 point questions and 14 5 point questions.