Solve the system of equations. 2x+2y+7z=9, 2x+6y+5z=7, 5x+2y+4z=9. a. x=3 y=-2 z=3 b. x=1 y=0 z=1 c. x=2 y=-1 z=0 d. x=0 y=1 z=2

1. a parachutist is 800 feet above the ground when she opens her parachute. she then falls at a constant rate of 5 feet per second. select the equation that represents this situation. h = -800t + 5 y = -5x + 800 h = 5t - 800 y = 800x + 5 i need

If the altitude is drawn to the hypotenuse of a right triangle, then the two triangles formed are similar to the original triangle and to each other. which set of triangles shows the similar triangles created by the altitude in the diagram?

Serena is making an experiment. for that, she needs 20 grams of a 52% solution of salt. she has two large bottles of salt water: one with 40% and the other with 70% of salt in them. how much of each must she use to make the solution she needs? i am in need of