Question

PLLELELELELLEASEEEEE T_T

Answer 1

${\qquad\qquad\huge\underline{{\sf Answer}}}$

let's solve ~

$\qquad \sf  \dashrightarrow \: \cfrac{7}{2a} + \cfrac{9}{10} = \cfrac{5}{12a}$

$\qquad \sf  \dashrightarrow \: \cfrac{7}{2a} - \cfrac{5}{12a} = - \cfrac{9}{10}$

$\qquad \sf  \dashrightarrow \: \cfrac{7(6) - 5}{12a} = - \cfrac{9}{10}$

$\qquad \sf  \dashrightarrow \: \cfrac{42 - 5}{12a} = - \cfrac{9}{10}$

$\qquad \sf  \dashrightarrow \: 37(10) = - 9(12a)$

$\qquad \sf  \dashrightarrow \: 370 = - 108a$

$\qquad \sf  \dashrightarrow \: a = - \cfrac{370}{108}$

$\qquad \sf  \dashrightarrow \: a = - \dfrac{185}{54}$