1. Sec 4.2B Solve One-Step Multiplication and Division Equationspg

2. Definitions The expression 3x means “3 times the value of x”
The numerical factor of a multiplication expression like 3x is called a COEFFICENT.
What is the coefficient of 4y? 4
What is the coefficient of -5a -5

3. Division Property of Equality
If you divide each side of an equation by the SAME NONZERO NUMBER, the two sides remain equal.
If a = b and c ≠ 0, then 𝑎 𝑐 = 𝑏 𝑐
Numbers
9 = 9
9 3 = 9 3
3 = 3
Algebra
3c = -12
3𝑐 3 = −12 3
c = -4

4. Solve Check! 6x = 24 6𝑥 6 = 24 6 6x = 24 x = 4 6(4) = 24 -2a = 20
6𝑥 6 = 24 6
x = 4
-2a = 20
−2𝑎 −2 = 20 −2
a = -10
6x = 24
6(4) = 24
24 = 24
-2a = 20
-2(-10) = 20
20 = 20

5. Mulitiplication Property of Equality
If you multiply each side of an equation by the SAME NUMBER, the two sides remain equal.
Numbers
4 = 4
4(-5) = 4(-5)
-20 = -20
Algebra
𝑥 5 =6
𝑥 5 5 =6(5)
x = 30

6. Solve −11= 𝑏 4 −11 4 = 𝑏 4 (4) Check! −11= 𝑏 4 −11= −44 4 -44 = b
−11 4 = 𝑏 4 (4)
= b
−11= 𝑏 4
−11= −44 4
-11 = -11

7. Formula
A formula is an equation that shows the relationship among certain quantities.
d = rt is a common one that shows the relationship between distance, rate and time.

8. Solve
The rate, r, driven by Mark can be calculated given that he travels 230 miles in 2.5 hours.
d = rt
230 miles = r (2.5 hours)
230 𝑚𝑖𝑙𝑒𝑠 2.5 ℎ𝑜𝑢𝑟𝑠 = (𝑟)(2.5 ℎ𝑜𝑢𝑟𝑠) 2.5 ℎ𝑜𝑢𝑟𝑠
92 miles per hour = r