Download Review Homework page 67

Review Homework page 67
1. 2 × 32
2. 23 × 32
3. prime 1 x 29
4. 22 × 52
5. true
6. false 32 × 7
7. 2 × 3 × 3 × 𝑥 × 𝑥 × 𝑥
8. −1 × 2 × 3 × 5 × 𝑠 × 𝑠 × 𝑡 × 𝑡 × 𝑡 × 𝑧
9. -75
10. 70𝑥 2 𝑦
11. odd yes 21 = 1,3,7,21 42 = 1,2,3,6,7,14,21,42
even - no 14 = 1,2,7,14 28=1,2,4,7,14,28
Common Factors 공약수
• Factors that are common to 2 or more
numbers. Each of the numbers has the same
factors.
• 12 – 1,2,3,4,6,12
• 18 – 1,2,3,6,9,18
• Common factors are 1,2,3,6
Greatest Common Factor (GCF)
최대공약수
• The largest of the common factors between
two or more numbers.
• 12 – 1,2,3,4,6,12
• 18 – 1,2,3,6,9,18
• GCF = 6
GCF involving variables
• Find the GCF of 12x2y3z and 18x5y
12x2y3z =2*2*3*x*x*y*y*y *z
18x5y = 2*3*3*x*x*x*x*x*y
=2*3*x*x*y =6x2y
You can find the GCF of the coefficients and then
choose each common variable term with the
lowest exponent.
• Page 72-73
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Practice
2
10
9
18
6,12 or 12, 18 or 6,18 or 12,30 …
9,18 or 9,27 or 18, 27 ….
2,4 or 2, 6 or 4,6 or 6,14 ….
10,20 or 10,30 or 20,30 …
Area 21 perimeter 20
Area 25 perimeter 20
yes 21=3 x 7 20 =2x2x5 no common factors
no common factor of 5
4𝑥 2 𝑦 2
Least Common Multiple (LCM)
최소공배수
• The smallest number that 2 or more numbers
both divide into evenly.
• multiples of
• 6 – 6,12,18,24,30,36,42,48,54,60,66,72,….
• 8 – 8,16,24,32,40,48,56,64,72,80,88,96,….
• common multiples are :24,48,72,…
• The smallest number they both have in
common is the LCM
LCM involving variables
• Find the LCM of 12x2y3 and 18x5yz
You can find the LCM of the coefficients and then
choose every variable term with the highest
exponent.
LCM of 12 and 18 is 36
the LCM is 36x5y3z
Practice
• page 75
1. 45
2. 84
3. 28xy
4. 60𝑥 2 𝑦 3
4 2
5. 108𝑥 𝑦
3 4
6. 112𝑥 𝑦
Homework
• Page 77-78
Page 77 - 78
1) 5
2) 3