giải
71/38/45-(43/8/45-1/17/57)
=71/38/45-43/8/45+1/17/57
=28/30/45+1/17/57
=1708/57
giải
71/38/45-(43/8/45-1/17/57)
=71/38/45-43/8/45+1/17/57
=28/30/45+1/17/57
=1708/57
tính hợp lí
71/38/45-(43/8/45-1/17/57)
tính hợp lý giá trị các biểu thức sau :
B= 71\(\dfrac{38}{45}\) - ( 43\(\dfrac{8}{45}\) - 1\(\dfrac{17}{57}\) )
D= ( 19\(\dfrac{5}{8}\) : \(\dfrac{7}{12}\) - 13\(\dfrac{1}{4}\) : \(\dfrac{7}{12}\) ) . \(\dfrac{4}{5}\)
F= ( 9,75 . 21\(\dfrac{3}{7}\) + \(\dfrac{39}{4}\) . 18\(\dfrac{4}{7}\) ). \(\dfrac{15}{78}\)
tính hợp lý giá trị các biểu thức sau :
A= \(49\frac{8}{23}-\left(5\frac{7}{32}+14\frac{8}{23}\right)\)
B= \(71\frac{38}{45}-\left(43\frac{8}{45}-1\frac{17}{57}\right)\)
C= \(\frac{-3}{7}.\frac{5}{9}+\frac{4}{9}.\frac{-3}{7}+2\frac{3}{7}\)
D = \(\left(19\frac{5}{8}:\frac{7}{12}-13\frac{1}{4}:\frac{7}{12}\right).\frac{4}{5}\)
E= \(0,7.2\frac{2}{3}.20.0,375.\frac{5}{28}\)
F= \(\left(9,75.21\frac{3}{7}+\frac{39}{4}.18\frac{4}{7}\right).\frac{15}{78}\)
tính hợp lí : \(\dfrac{38}{45}-\left[\dfrac{8}{45}-\dfrac{17}{51}-\dfrac{3}{11}\right]\)
BT1: Tính nhanh:
1) 45 . ( 13 + 78 ) + 9 . ( 87 + 22 ) .5
2) 43 . 37 + 93 . 43 + 57 . 61 + 69 . 57
Tính bằng cách hợp lý:
a, 16.(38-2).38.(16-1)
b,(-25).(75-45)-75(45-25)
1, 72-3.|x+1|=9
2, 17-(43-|x|)=45
72-3.|x+1|=9
17-(43-|x|)=45
3|x-1|-5=7
Giúp mk vs các bạn ơi
Bỏ ngoặc rồi tính :
a, - ( - 15 + 125 - 81 ) - ( - 85 + 75 - 19 + 100 )
b, ( 39 - 48 + 57 ) - ( - 61 + 52 + 157 )
c, ( -25 - 65 + 30 ) - ( 75 - 65 - 170 )
d, - ( - 45 - 135 + 29 ) + ( 55 - 35 - 71 )