tính
2 3
____ + ______
3 51
b) 34 19 3
_____ – ______ – _______
31 28 31
c) 18 55 5
_____ + ______ – ______
36 46 13
Đáp án:
Giải thích các bước giải:
$\frac{2}{3}$ + $\frac{3}{51}$ = $\frac{37}{51}$
b)$\frac{34}{31}$ – $\frac{19}{28}$ – $\frac{3}{31}$ = $\frac{9}{28}$
c)$\frac{18}{36}$ + $\frac{55}{46 }$ -$\frac{5}{13}$ = $\frac{392}{299}$
$\frac{2}{3}$+ $\frac{3}{51}$
= $\frac{34}{51}$ + $\frac{3}{51}$
= $\frac{34+3}{51}$
= $\frac{37}{51}$
$\frac{34}{31}$ – $\frac{19}{28}$ -$\frac{3}{31}$
=( $\frac{34}{31}$ – $\frac{3}{31}$) – $\frac{19}{28}$
= $\frac{31}{31}$ – $\frac{19}{28}$
= 1- $\frac{19}{28}$
= $\frac{9}{28}$
= $\frac{18}{13}$ + $\frac{55}{46}$ -$\frac{5}{13}$
= ($\frac{18}{13}$ – $\frac{5}{13}$ )+ $\frac{55}{46}$
= $\frac{13}{13}$ + $\frac{55}{46}$
= 1 + $\frac{55}{46}$
= 1$\frac{55}{46}$