Question

calculati a)3-(1-1/4)-(4-7/2)
b)3 1/3+2 1/5-(7/15+2 1/3)

Answer 1

A)
$3 - (1 - \frac{1}{4} ) - (4 - \frac{7}{2} ) =$


$3 - \frac{4 - 1}{4} - \frac{2 \times 4 - 7}{2} = 3 - \frac{3}{4} - \frac{1}{2}$


$= \frac{3 \times 4 - 3 - 2 \times 1}{4} = \frac{12 - 3 - 2}{4} = \frac{7}{4}$
B)
$3 \frac{1}{3} + 2 \frac{1}{5} - ( \frac{7}{15} + 2 \frac{1}{3} )$



$\frac{3 \times 3 + 1}{ 3} + \frac{2 \times 5 + 1}{5} - ( \frac{7}{15} + \frac{2 \times 3 + 1}{3} )$



$= \frac{10}{3} + \frac{11 }{5} - ( \frac{7}{15} + \frac{7}{3} ) =$



$= \frac{10}{ 3} + \frac{11}{5} - \frac{7 + 5 \times 7}{15} =$



$\frac{5 \times 10 + 3 \times 11 - 7 + 35}{15} = \frac{50 + 33 - 42}{15} = \frac{41}{15}$