algebra readiness lesson 2-5 warm up. algebra readiness lesson 2-5 warm up
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ALGEBRA READINESS “Dividing Integers” (2-5) What are the rules for dividing positive and negative numbers? NOTE: You can use same rules for multiplying positives and negatives. Rule: Dividing Numbers With the Same Sign: The quotient of two positive or two negative numbers is positive. Examples: 6 ÷ 3 = 2 : -6 ÷ (-3) = 2 Rule: Multiplying Numbers With Different Signs: The quotient of two numbers with opposite signs (a “+” number divided by a “–” number or a “-” number divided by a “+” number) is negative. Examples: -6 ÷ 3 = -2 : 6 ÷ -3 = -2TRANSCRIPT
ALGEBRA READINESS
LESSON 2-5Warm Up
ALGEBRA READINESS
LESSON 2-5Warm Up
ALGEBRA READINESS
“Dividing Integers” (2-5) What are the rules for dividing positive and negative numbers?
NOTE: You can use same rules for multiplying positives and negatives.
Rule: Dividing Numbers With the Same Sign: The quotient of two positive or two negative numbers is positive.Examples: 6 ÷ 3 = 2 : -6 ÷ (-3) = 2
Rule: Multiplying Numbers With Different Signs: The quotient of two numbers with opposite signs (a “+” number divided by a “–” number or a “-” number divided by a “+” number) is negative.Examples: -6 ÷ 3 = -2 : 6 ÷ -3 = -2
ALGEBRA READINESS
Simplify each expression.
a. 70 ÷ (–5)
b. –54 ÷ (–9)
The quotient of a positive number and a negative number is negative.= –14
The quotient of a negative number and a negative number is positive.
= 6
Dividing IntegersLESSON 2-5
Additional Examples
ALGEBRA READINESS
Evaluate – – 4z2 for x = -4, y = –2, and z = –4.
= – 4 (16) Simplify the power.–4–2
= 2 – 64 Divide and multiply.
= –62 Subtract.
xy
– – 4z2 = – 4(–4)2 Substitute -4 for x, –2 for y, and –4 for z.xy
–4–2
Dividing IntegersLESSON 2-5
Additional Examples
ALGEBRA READINESS
Evaluate for p = and r = – .
= –2 Simplify.
pr
32
34
= p ÷ r Rewrite the equation.pr
= ÷ Substitute for p and – for r.34(– )3
232
34
= Multiply by the reciprocal of - – = - – .43
– 32
43
34
Dividing IntegersLESSON 2-5
Additional Examples
ALGEBRA READINESS
In a 2-hour period, the wind speed decreased from 28 mph to 18 mph. If the speed decreased the same amount each hour, how much did the wind speed change each hour?
–10 ÷ 2 = r
The wind speed changed at an average rate of –5 mph each hour.
Words total divided number equals changechange by of hours per hour
Let r = the average change per hour.
Equation –10 ÷ 2 = r
–5 = r different signs, negative quotient
Dividing IntegersLESSON 2-5
Additional Examples
ALGEBRA READINESS
Find each quotient.
1. –27 ÷ (–3) 2. 30 ÷ (–6)
9 –5
Dividing IntegersLESSON 2-5
Lesson Quiz