91Ó°ÊÓ

Evaluate each algebraic expression for the given value or values of the variable(s). $$x^{2}+3 x, \text { for } x=8$$

A football was kicked vertically upward from a height of 4 feet with an initial speed of 60 feet per second. The formula $$h=4+60 t-16 t^{2}$$ describes the ball's height above the ground, \(h,\) in feet, \(t\) seconds after it was kicked. Use this formula to solve Exercises \(19-20 .\) What was the ball’s height 2 seconds after it was kicked?

List all numbers from the given set that are a. natural numbers, b. whole numbers, c. integers, d. rational numbers, e. irrational numbers, f. real numbers. $$\left\\{-11,-\frac{5}{6}, 0,0.75, \sqrt{5}, \pi, \sqrt{64}\right\\}$$

Factor each trinomial, or state that the trinomial is prime. $$6 x^{2}-7 x y-5 y^{2}$$

In Exercises \(45-54,\) rationalize the denominator. $$\frac{\sqrt{7}}{\sqrt{3}}$$

Factor each perfect square trinomial. $$4 x^{2}+4 x+1$$

Factor completely, or state that the polynomial is prime. $$5 x^{3}-45 x$$

Simplify the radical expressions in Exercises \(67-74\) if possible. $$\sqrt[3]{150}$$

In Exercises \(83-90\), evaluate each expression without using a calculator. $$121^{\frac{1}{2}}$$

Factor and simplify each algebraic expression. $$x^{\frac{3}{4}}-x^{\frac{1}{4}}$$