91Ó°ÊÓ

Simplify the expression. (Lesson 2.3)$2n−7(n−8)$

Challenge When mathematician Carl Friedrich Gauss was a child, his teacher is said to have asked Gauss and his classmates to add up the integers 1 through 100. Gauss found the answer almost immediately. He first wrote the sum forwards and backwards, as shown

1. You can pair each number in the top sum with the number below it in the bottom sum. What is the sum of the numbers in each pair?
2. How many pairs of numbers are there?
3. Use your answers from parts (a) and (b) to complete this statement: If S is the sum of the integers 1 through 100, then 2S _?_.
4. Interpret What is the sum of the integers 1 through 100? Explain.

Perform the indicated operation.

$5(-14)$

Multiple Choice Which terms are not like terms?

$\begin{array}{l}A.\text{ â¶Ä‰}8y\text{and}−4y\\ B.\text{ â¶Ä‰}2\text{and}3.14\\ C.\text{ â¶Ä‰}{x}^2\text{and}{x}^5\\ D.\text{ â¶Ä‰}{x}^2\text{and}5x^2\end{array}$

Perform the indicated operation. (Lessons 1.5–1.7)

$-23(-8)$

Evaluate the power. (Lesson 1.2)

${\left(2.5\right)}^3$

Which expression is equivalent to $8t−6(2t−1)$?

$\begin{array}{l}F.4t+6\\ G.−4t−6\\ H.−4t−1\\ I.−4t+6\end{array}$

Solve the equation. Check your solution.

$y-9=-4$

Evaluate the expression.

$3^4$

Multiple Choice Two more than a number is 8. Which equation can you solve to find the number?

$A:2x=8\text{ â¶Ä‰â€‰â¶Ä‰â€‰â¶Ä‰â€‰â¶Ä‰}B:\text{ â¶Ä‰}x+2=8\text{ â¶Ä‰â€‰â¶Ä‰â€‰â¶Ä‰â€‰â¶Ä‰â€‰â¶Ä‰}C:\text{ â¶Ä‰}x+8=2\text{ â¶Ä‰â€‰â¶Ä‰â€‰â¶Ä‰â€‰â¶Ä‰â€‰â¶Ä‰}D:\text{ â¶Ä‰}2+8=x$