Which of the following statements best explains the abundance of oxygen in the earth's atmosphere? A. Plants create oxygen as a byproduct of photosynthesis. B. The sun's radiation produces oxygen, which travels rapidly through space and enters the atmosphere. C. Industrial emissions from factories add large amounts of oxygen and nitrogen to the earth's atmosphere. D. The ozone layer of the stratosphere produces oxygen during the summer when temperatures are warmest.

How have climate zones affected trade in the Andes? A.Many people prefer to work in the mining industry, which is less affected by climate. B. People trade items from different latitudes and longitudes. C. Andean Indians have, over centuries, developed larger hearts and lungs for living in thin air. D. Many people grow crops suited to their climate zone and rely on "vertical trade."

How have tectonic plate boundaries affected physical characteristics in Latin America? A. Plate movement created the Andes Mountains along the west coast of South America. B. Plate spreading increases the size of South America by 5 percent every 100 years. C. Many volcanoes lie along South America's east coast. D. Plate movement causes the Amazon Basin to sink, lowering the average elevation of the region.

Use the piecewise-defined function to find the following values for f(x).

$$f(x)=\begin{cases} 1-2x & \text{if $x\leq 1$}\\ 2x & \text{if $1\lt x\lt 9$}\\ 4x+4 & \text{if $x\geq 9$} \end{cases}$$

f(-5) = ___ f(-2) = ___

Is the first number divisible by the second? Explain. 69 by 3

Solve each system of equations using Cramer’s Rule if it is applicable. If Cramer’s Rule is not applicable, say so.

$$\left\{\begin{array}{l}{5 x-y=13} \\ {2 x+3 y=12}\end{array}\right.$$

Marian borrowed money to buy a sound system that costs $450. She is charged 5% simple interest for one year. What is the total amount that she pays for the sound system if she pays the full amount in one year? Show your work.

Identify the following term or individuals and explain their significance. filibuster

A school district has 57 new laptop computers to be divided among four schools, according to their respective enrollments. The table shows the number of students enrolled in each school.

$$\begin{matrix} \text{School} & \text{A} & \text{B} & \text{C} & \text{D} & \text{Total}\\ \text{Enrollment} & \text{5040} & \text{4560} & \text{4040} & \text{610} & \text{14.250}\\ \end{matrix}$$

a. Apportion the laptop computers using Hamilton’s method. b. Use Hamilton’s method to determine if the Alabama paradox occurs if the number of laptop computers is increased from 57 to 58. Explain your answer.

(A) Write an equation in terms of x that represents the given relationship. (B) Solve the equation to find the dimensions of the given shape.

A rectangular garden covers 40 yd^2. The length is 2 d longer than the width. Find the length and width. Round to the nearest tenth of a yard.

Find the length of the curve.

$$x = ( 2 t + 3 ) ^ { 3 / 2 } / 3 , \quad y = t + t ^ { 2 } / 2 , \quad 0 \leq t \leq 3$$

Jake is installing a staircase so his children can have access to a tree house he built. The rise of the stairs is 7 inches and the run of each stair Is 10 Inches. What is the slope of the staircase, expressed as a fraction?

Consumers spend $95 million on Father's Day cards and$152 million on Mother's Day cards. What is the amount of increase or decrease from Mother's Day to Father's Day cards? What percentage of the combined total do consumers spend on Mother's Day cards?

Evaluate the following integral. $\int \frac{\cos x}{\sin ^{7 / 4} x} d x$