Core Connections Algebra 1, 2013
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Core Connections Algebra 1, 2013 View details
2. Section 2.2
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Exercise 72 Page 74

Practice makes perfect
a We can rewrite any mixed number as a fraction by adding the product of the whole number and the denominator to whatever is in the numerator.
8 25Ă· 3 14
42/5Ă· 13/4
42/5 * 4/13
168/65

If we want to rewrite this fraction as a mixed number, we have to determine how many times 65 goes into 168. Since 65* 1=65, we know that it goes at least 1 time into 65. Let's continue from that. &1* 65= 65 &2* 65= 130 &3* 65 = 195 As we can see, 65 goes at most 2 times into 168, which becomes the whole number part of our mixed number. To find the fraction part, we have to subtract 130 from 168. 168-130=38 The mixed number is 2 3865.

b We solve the next exercise in the same way as in Part A, by first rewriting the mixed numbers as fractions.
5 12* (- 6 34)
11/2* (-27/4)
- 11/2 * 27/4
- 297/8

Let's rewrite this as a mixed number. Since 8* 30=240, we know that 8 goes at least 30 times into 297. Let's continue from that. 8* 30= 240 8* 31= 248 8* 32= 256 8* 33 = 264 8* 34 = 272 8* 35 = 280 8* 36 = 288 8* 37 = 296 8* 38 = 304 As we can see, 8 goes 37 times into 297 which becomes the whole number part of our mixed number. To find the fraction part, we have to subtract 296 from 297. 297-296=1 The mixed number is 37 18.

c When we have a subtraction of two mixed numbers, we should rewrite the mixed numbers as sums. Note that 3 58 and 1 12 can be interpreted as the statements three and five eights and one and one half.
ccc three & and & five eights 3 & + & 5/8 one & and & one half 1 & + & 1/2Now we can evaluate the expression.
- (3+5/8)-(1+1/2)
- 3-5/8-1-1/2
- 4-5/8-1/2
- 4-5/8-4/8
- 4-9/8
Note that 98 can be rewritten as 1+ 18. - 4-(1+ 18)=- (5 +1/8) Written as a mixed number, we have - 5 18.
d To evaluate the expression we have to rewrite - 7 as a fraction.
- 7+2/3
- 21/3 + 2/3
- 21+2/3
- 19/3
- 19/3

Let's rewrite this as a mixed number. Since 3* 5=15, we know that 3 goes at least 5 times into 19. Let's continue from that. 3* 5= 15 3* 6= 18 3* 7 = 21 As we can see, 3 goes 6 times into 19, which becomes the whole number part of our mixed number. To find the fraction part we have to subtract 18 from 19. 19-18=1 The mixed number is - 6 13.