Question

solve for 50 points. all

Answer 1

Hey there!!

(1). $\dfrac{3}{7}$ + $\dfrac{4}{9}$ - $\dfrac{-11}{7}$ - $\dfrac{7}{9}$

= $\dfrac{3}{7}$ - $\dfrac{4}{9}$ + $\dfrac{11}{7}$ - $\dfrac{7}{9}$

After that , we take LCM of 7,9,7,9

which is 63

= $\dfrac{3 × 9 - 7 × 4 + 9 × 11 - 7 × 7}{63}$

= $\dfrac{27 - 28 + 99 - 45}{63}$

= $\dfrac{126 - 77}{63}$

= $\dfrac{49}{63}$

we can also write it as

= $\dfrac{7}{9}$

(2). $\dfrac{2}{5}$ + $\dfrac{-4}{5}$ - $\dfrac{1}{3}$ - $\dfrac{2}{5}$

= $\dfrac{2 × 5 - 3 × 4 - 5 × 1 - 3 × 2}{15}$

= $\dfrac{10 - 12 - 5 - 6}{15}$

= $\dfrac{10 - 23}{15}$

= $\dfrac{-13}{15}$

(3). $\dfrac{4}{7}$ - $\dfrac{-8}{9}$ - $\dfrac{-13}{7}$ + $\dfrac{17}{9}$

= $\dfrac{4}{7}$ + $\dfrac{8}{9}$ + $\dfrac{13}{7}$ + $\dfrac{17}{9}$

= $\dfrac{4 × 9 + 7 × 8 + 13 × 9 + + 17 × 7}{63}$

= $\dfrac{36 + 56 + 117 + 119}{63}$

= $\dfrac{328}{63}$
____________________
HOPE IT HELPS YOU OUT✔