Tihns thuận tiện: a) 3/4 + 1/2 + 1/4 = b) 54 . 45 + 54 . 55 =

2 câu trả lời

a) 3/4 + 1/2 + 1/4 =  (3/4 + 1/4) + 1/2 = 1+1/2 = 3/2

b) 54 . 45 + 54 . 55 = 54. (45+55) = 54 . 100 = 5400

$a,\frac{3}{4}+\frac{1}{2}+\frac{1}{4}$

$=\frac{3}{4}+\frac{1}{4}+\frac{1}{2}$

$=\frac{4}{4}+\frac{1}{2}$

$=1+\frac{1}{2}$

$=\frac{2}{2}+\frac{1}{2}$

$=\frac{3}{2}$

$b,54.45+54.55$

$=54(45+55)$

$=54.100$

$=5400$