Đáp án + Giải thích các bước giải:
Bài 4:
a, x+ $\frac{7}{-2}$ = $\frac{3}{4}$
-> x = $\frac{3}{4}$ - $\frac{7}{-2}$
-> x = $\frac{3}{4}$ + $\frac{14}{4}$
-> x = $\frac{17}{4}$
Vậy...
b, 9x - $\frac{14}{9}$ = $\frac{-2}{9}$
-> 9x = $\frac{-2}{9}$ + $\frac{14}{9}$
-> 9x = $\frac{12}{9}$
-> x = $\frac{4}{3}$ : 9
-> x = $\frac{4}{27}$
Vậy...
c, $\frac{-1}{2}$ : ( x - $\frac{1}{3}$ ) = - $\frac{3}{4}$
-> x - $\frac{1}{3}$ = $\frac{-1}{2}$ : ( - $\frac{3}{4}$ )
-> x - $\frac{1}{3}$ = $\frac{-1}{2}$ . $\frac{-4}{3}$
-> x - $\frac{1}{3}$ = $\frac{2}{3}$
-> x = $\frac{2}{3}$ + $\frac{1}{3}$
-> x = $\frac{3}{3}$ = 1
Vậy...
d, ( x - 3.5 ) : 3$\frac{1}{2}$ - 2.5 = -1$\frac{3}{4}$
-> ( x - 15 ) : $\frac{7}{2}$ - 10 = - $\frac{7}{4}$
-> ( x - 15 ) : $\frac{7}{2}$ = - $\frac{7}{4}$ + 10
-> ( x - 15 ) : $\frac{7}{2}$ = $\frac{33}{4}$
-> x - 15 = $\frac{33}{4}$ . $\frac{7}{2}$
-> x - 15 = $\frac{231}{8}$
-> x = $\frac{231}{8}$ + 15
-> x = $\frac{351}{8}$
Vậy...
~Gaconcute1809~
