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+60t-16t² 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?

Simplify the algebraic expression. (1/5)(5x) + [(3y) + (- 3y)] - (-x)

Evaluate each exponential expression in Exercises 1–22. $2^3/2^7$

Use the product rule to simplify the expressions in Exercises 13–22. In Exercises 17–22, assume that variables represent nonnegative real numbers. $\sqrt{2x^2}\cdot \sqrt{6x}$

Find the intersection of the sets. {1,2,3,4}∩{2,4,5}

Multiply or divide as indicated. $\frac{x^3 - 8}{x^2 - 4} \cdot \frac{x + 2}{3x}$

In Exercises 17–38, factor each trinomial, or state that the trinomial is prime. x²−14x+45

Use the product rule to simplify the expressions in Exercises 13–22. In Exercises 17–22, assume that variables represent nonnegative real numbers. $\sqrt{6x}\cdot \sqrt{3x^2}$

Find each product. (x−1)(x+2)

Find the intersection of the sets. {s,e,t}∩{t,e,s}

Simplify each exponential expression in Exercises 23–64. x⁻²y

Multiply or divide as indicated. $\frac{x + 5}{7} \div \frac{4x + 20}{9}$

Use the quotient rule to simplify the expressions in Exercises 23–32. Assume that x > 0. $\sqrt{\frac{1}{49}}$

In Exercises 17–38, factor each trinomial, or state that the trinomial is prime. 2x^2+5x−3

Evaluate each exponential expression: (-3)³ (-2)²

Evaluate each exponential expression: 2^(-4) + 4^(-1)

Simplify each exponential expression in Exercises 23–64. $x^0{y}^5$

In Exercises 15–32, multiply or divide as indicated. (x²−4)/(x−2) ÷ (x+2)/(4x−8)

Evaluate each exponential expression: 5^-3• 5

Find each product. (2x−5)(7x+2)

Find the intersection of the sets. {a,b,c,d}∩∅

In Exercises 17–38, factor each trinomial, or state that the trinomial is prime. 6x²−11x+4

Use the quotient rule to simplify the expressions in Exercises 23–32. Assume that x > 0. √48x³/√3x

Evaluate each exponential expression: (3³)/(3⁶)

In Exercises 15–32, multiply or divide as indicated. (x²+x)/(x²−4) ÷ (x²−1)/(x²+5x+6)

Simplify each exponential expression: $(-2x^4{y}^3{)}^3$

In Exercises 15–58, find each product. (7x²−2)(3x²−5)

Use the quotient rule to simplify the expressions in Exercises 23–32. Assume that x > 0. $\frac{\sqrt{150x^4}}{\sqrt{3x}}$

Simplify each exponential expression in Exercises 23–64. $x^{-5}\cdot x^{10}$