Question

Answer 1

`@` `\text {Ans}`

`\downarrow`

`a)`

`A=(-2/3 + 3/7) \div 4/6 + (-1/3+4/7) \div 4/5`

`= -5/21 \div 4/6 + 5/21 \div 4/5`

`= -5/21 * (6/4 - 5/4)`

`= -5/21*1/4`

`= -5/84`

`b)`

`B= (-2/3+3/7) \div 4/5 + (-1/3+4/7) \div 4/5`

`= (-2/3+3/7)*5/4 + (-1/3+4/7)*5/4`

`= 5/4*(-2/3+3/7-1/3+4/7)`

`= 5/4*[(-2/3-1/3)+(3/7+4/7)]`

`= 5/4*(-1+1)`

`= 5/4*0=0`

`c)`

`C=5/9 \div (1/11-5/22) + 5/9 \div (1/15-2/3)`

`= 5/9 \div (-3/22) + 5/9 \div (-3/5)`

`= 5/9*(-22/3) + 5/9*(-5/3)`

`= 5/9*(-22/3-5/3)`

`= 5/9*-9`

`= -5`

Answer 2

a: \(=\dfrac{-14+9}{21}\cdot\dfrac{6}{4}+\dfrac{-7+12}{21}\cdot\dfrac{5}{4}\)

\(=\dfrac{-5}{21}\cdot\dfrac{3}{2}+\dfrac{5}{21}\cdot\dfrac{5}{4}\)

=5/21(-3/2+5/4)

=5/21*(-1/4)=-5/84

b: \(=\left(-\dfrac{2}{3}+\dfrac{3}{7}\right)\cdot\dfrac{5}{4}+\left(\dfrac{-1}{3}+\dfrac{4}{7}\right)\cdot\dfrac{5}{4}\)

=5/4(-2/3+3/7-1/3+4/7)

=0

c: \(=\dfrac{5}{9}:\left(\dfrac{1}{11}-\dfrac{5}{22}+\dfrac{1}{15}-\dfrac{2}{3}\right)\)

\(=\dfrac{5}{9}:\left(\dfrac{-3}{22}+\dfrac{-3}{5}\right)\)

\(=\dfrac{5}{9}:\dfrac{-81}{110}=\dfrac{-5}{9}\cdot\dfrac{110}{81}=\dfrac{-550}{729}\)