Question

Приведите подобные слагаемые:
А) 2/3b+19/21b;
B)-2/3b-19/21b;
C)-2/3b+19/21b;
D)1/2a+3/5a;

Answer 1

$1) frac{2}{3} b + frac{19}{21}b = frac{14b+19b}{21} = frac{33b}{21} = frac{11b}{7} \ \ 2) - frac{2}{3} b - frac{19}{21}b = frac{-14b-19b}{21} = frac{-33b}{21} = frac{-11b}{7} \ \ 3) - frac{2}{3} b + frac{19}{21}b = frac{-14b+19b}{21}} = - frac{5b}{21} \\ 4) frac{1}{2}a+frac{3}{5}a = frac{5a+6a}{10} = frac{11a}{10}$