Question

mixed review

1. *compute: -129.53 - -13.79
2. compute: -4\frac{3}{9} - 10\frac{1}{4}
3. compute: (-1\frac{2}{3})(9\frac{3}{4})
4. *write as a decimal: \frac{7}{16}
5. ***mr. loureiro arrives at school at 7am. he starts the day with 9 sharpened pencils. he asks annel to sharpen pencils. annel sharpens eleven pencils every minute for the next seven minutes. what was the number of sharpened pencils at 7:07am?

Explanation:

Step1: Rewrite subtraction as addition

$129.53 - (-13.79) = 129.53 + 13.79$

Step2: Add the two decimals

$129.53 + 13.79 = 143.32$

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Step1: Convert mixed numbers to fractions

$-4\frac{1}{3} = -\frac{13}{3}$, $10\frac{1}{2} = \frac{21}{2}$

Step2: Subtract the fractions

$-\frac{13}{3} - \frac{21}{2} = -\frac{26}{6} - \frac{63}{6}$

Step3: Calculate the result

$-\frac{26 + 63}{6} = -\frac{89}{6} = -14\frac{5}{6}$

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Step1: Convert mixed numbers to fractions

$-3\frac{2}{3} = -\frac{11}{3}$, $5\frac{1}{2} = \frac{11}{2}$

Step2: Multiply the fractions

$-\frac{11}{3} \times \frac{11}{2} = -\frac{121}{6} = -20\frac{1}{6}$

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Step1: Divide numerator by denominator

$\frac{7}{20} = 7 \div 20$

Step2: Calculate the decimal value

$7 \div 20 = 0.35$

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Step1: Calculate pencils sharpened in 7 min

$11 \times 7 = 77$

Step2: Add initial sharpened pencils

$9 + 77 = 86$

Answer:

1. $143.32$
2. $-\frac{89}{6}$ or $-14\frac{5}{6}$
3. $-\frac{121}{6}$ or $-20\frac{1}{6}$
4. $0.35$
5. $86$