Chapter 2: Algebra Solve Equations And Inequalities
Review What You Know
Page 80 Exercise 1 Answer
In 6x, x is a(n) variable.
Result
Variable
Page 80 Exercise 2 Answer
x + 5 is an example of a(n) algebraic expression.
Result
Algebraic Expression
Page 80 Exercise 3 Answer
Evaluate an expression to find its value.
Result
Evaluate
Page 80 Exercise 4 Answer
6 + 2 Given
= 2 + 6 Commutative Property of Addition
Result
6 + 2 = 2 + 6
TRUE
Page 80 Exercise 5 Answer
2.5 − 1 = 1.5 Subtract
1 − 2.5 = −1.5 Subtract
Result
2.5 − 1 ≠ 1 − 2.5
FALSE
Page 80 Exercise 6 Answer
\(\frac{1}{2}\) x 3 = 3 x \(\frac{1}{2}\) Commutative Property of Multiplication: a × b = b × a
Result
TRUE
Page 80 Exercise 7 Answer
\(\frac{3}{4}\) ÷ 5 Given
= \(\frac{3}{4}\) x \(\frac{1}{5}\) Rewrite Division as Multiplication
Result
\(\frac{3}{4} \div 5=\frac{3}{4} \times \frac{1}{5}\)TRUE
Page 80 Exercise 8 Answer
\(5 \div \frac{1}{3}=5 \times 3=15\) Rewrite Division as Multiplication
\(\frac{5}{3}=1.66\) Divide
Result
\(5 \div \frac{1}{3} \neq \frac{5}{3}\)FALSE
Page 80 Exercise 9 Answer
\(\frac{2}{3}\) x 5 Given
= \(\frac{2}{3}\) x \(\frac{5}{1}\) Write 5 as a fraction
= \(\frac{10}{3}\) Multiply
Result
\(\frac{2}{3}\) x 5 ≠ \(\frac{10}{15}\)
FALSE
Page 80 Exercise 10 Answer
x − 2 Evaluate
= 8 − 2 Substitute x = 8
= 6 Subtract
Result
6
Page 80 Exercise 11 Answer
2b Evaluate
= 2(9) Substitute b = 9
= 18 Multiply
Result
18
Page 80 Exercise 12 Answer
\(3 \frac{3}{4}\) + y Evaluate
= \(\frac{15}{4}\) + \(\frac{5}{6}\) Substitute y = \(\frac{5}{6}\)
= \(\frac{45+10}{12}\) LCM is 12
= \(\frac{55}{12}\) Simplify
Result
\(\frac{55}{12}\)Page 80 Exercise 13 Answer
\(\frac{15}{x}\) Evaluate
= \(\frac{15}{3}\) Substitute x = 3
= 5 Divide
Result
5
Page 80 Exercise 14 Answer
5.6t Evaluate
= 5.6(0.7) Substitute t = 0.7
= 3.92 Multiply
Result
3.92
Page 80 Exercise 15 Answer
4x Evaluate
= \(4\left(\frac{1}{2}\right)\) Substitute x = \(\frac{1}{2}\)
= 2 Multiply
Result
2
Page 80 Exercise 16 Answer
[(33 ÷ 3) + 1] − \(2^2\)
Order of Operation :
1. Evaluate the parentheses and bracket.
2. Evaluate the power.
3. Subtract.
[(33 ÷ 3) + 1] − \(2^2\)
= [11 + 1] − \(2^2\) Evaluate the parentheses
= 12 − \(2^2\) Evaluate the bracket
= 12 − 4 Evaluate the power
= 8 Subtract
Result
8