1. Simplify the expression and show the check of your answer.  Assume that x and yrepresent nonnegative real numbers:

3√(-1000x²⁴/27y¹⁵)

2. Use radical notation to rewrite the expression.  Simplify if possible:

(16)^3/4 + (-125)^2/3

3. Perform the indicated operations and simplify if possible:

[(√3x- 2)-7]²

4. Rationalize the denominator and simplify if possible:

15/√11 + 6

5. Solve the equation and show the check:

√(2x - 3) - 7 = -4

6. Solve the equation and show the check:

x = √(x+7)+5

7. A building has a ramp to its front door.  If the distance from the building to the end of the ramp is 20 feet and the height from the ground to the front doors is 4 feet, how long is the ramp?  Write an exact answer in simplified radical form and a decimal approximation, correct to the nearest tenth.