tinh hop ly cac bieu thuc sau
a 13 nhan3 nhan 32;37 cong 67;63 nhan 39
tinh cac bieu thuc sau
a)1/2 + -3/8 + 5/9
b) 13/-30+17/45+-7/18
c)-5/19+7/4-(-2/3)+5/6
a: \(\dfrac{1}{2}+\dfrac{-3}{8}+\dfrac{5}{9}\)
\(=\dfrac{36}{72}-\dfrac{27}{72}+\dfrac{40}{72}\)
\(=\dfrac{49}{72}\)
b: \(\dfrac{13}{-30}+\dfrac{17}{45}+\dfrac{-7}{18}\)
\(=\dfrac{-13}{30}+\dfrac{17}{45}+\dfrac{-7}{18}\)
\(=\dfrac{-39+34-35}{90}=\dfrac{-40}{90}=-\dfrac{4}{9}\)
c: \(-\dfrac{5}{19}+\dfrac{7}{4}-\left(-\dfrac{2}{3}\right)+\dfrac{5}{6}\)
\(=-\dfrac{5}{19}+\dfrac{7}{4}+\dfrac{2}{3}+\dfrac{5}{6}\)
\(=\dfrac{-5}{19}+\dfrac{21+8+10}{12}\)
\(=-\dfrac{5}{19}+\dfrac{39}{12}=\dfrac{-5}{19}+\dfrac{13}{4}=\dfrac{227}{76}\)
tinh gia tri cua bieu thuc sau bang cach hop ly 7
=
TINH GIA TRI BIEU THUC LABANG CACH HOP LY
( 145 X 99 + 145 ) - ( 143 X 101 - 143 )
( 145 X 99 + 145 ) - ( 143 X 101 - 143 )
= ( 145 x (99 + 1) ) - (143 x (101 - 1)
= 14500 - 14300
= 200
( 145 X 99 + 145 ) - ( 143 X 101 - 143 )
= ( 145 x (99 + 1) ) - (143 x (101 - 1)
= 14500 - 14300
= 200
( 145 X 99 + 145 ) - ( 143 X 101 - 143 )
= ( 145 x (99 + 1) - (143 x (101 - 1)
= 14500 - 14300
= 200
tinh gia tri bieu thuc sau bang cach hop ly
1-6+11-16+21+...+91-96+101
1-6+11-16+21-...+91-96+101 =(1-6)+(11-16)+(21-26)+....+(91-96)+101 =(-5)+(-5)+.....+(-5)+101 (có 10 số (-5) ) =(-5).10+101 =-50+101 =51
Tinh hop ly cac gia tri bieu thuc sau
a) \(4\frac{8}{23}+5\frac{7}{8}-9\frac{8}{23}\)
b)\(6\frac{3}{8}+5\frac{1}{2}\)
Tinh hop ly gia tri cac bieu thuc sau
a) \(\left(19\frac{5}{8}:\frac{7}{12}-13\frac{1}{2}:\frac{7}{12}\right).\frac{4}{5}\)
b) \(\left(\frac{377}{-231}-\frac{123}{89}+\frac{34}{791}\right).\left(\frac{1}{6}-\frac{1}{8}-\frac{1}{24}\right)\)
Tinh hop ly gia tri bieu thuc sau
\(\frac{1}{1.3.5}+\frac{1}{3.5.7}+...+\frac{1}{17.19.21}\)
Tinh hop ly gia tri cua cac bieu thuc sau
c)\(\frac{-5}{7}.\frac{3}{9}+\frac{4}{9}:\frac{-7}{3}\)
d) \(8\frac{2}{7}-\left(3\frac{4}{9}+4\frac{2}{7}\right)\)
c) =-5/7x3/9+4/9x3/-7
=-5/7x3/9+3/9x4/-7
=3/9x(-5/7+4/-7)
=3/9x-9/7
=-3/7
d) =58/7 - (31/9+30/7)
=58/7-31/9-30/7
=(58/7-30/7)-(31/9)
=4-31/9
=5/9
tinh gia tri bieu thuc mot cach hop ly
a , 125. (- 61 ) . (-2 )3 . ( - 1 )2.n ( n thuoc N*)
125.(-61).(-8).1
=[125.(-8)].[-61.1]
=-1000.(-61)
=61000