Solve by Elimination:
3x - 5y = -7
-4x + 7y = 8

Me! 50 points! why does when we come home, our door is unlocked and there is grease on the door knob, me solve this , and i don't know what category this goes under

The fence around a quadrilateral-shaped pasture is 3a^2+15a+9 long. three sides of the fence have the following lengths: 5a, 10a-2, a^2-7. what is the length of the fourth side of the fence?

If f(x) = 2x + 8 and g(x) = x4, what is (gº)?