146/13 -( 16/7 - 65/13)
tim tỉ số A/B biết
A=34/7*13+51/13*22+85/22*37+68/37*49
B=39/7*16+65/16*31+52/31*43+26/43*49
tinh a/b biet a=24/7*13+51/13*22+85/22*37+68/37*49
b=39/7*16+65/16*31+52/31*43+26/43*49
146/13 - ( 18/7 + 68/ 13)
=146/13-68/13+18/7
=78/13+18/7
=6+18/7
=42/7+18/7
=60/7
k nha
146/13 - ( 18/7 + 68/ 13)
= 146/13 - 18/7 - 68/ 13
= 146/13 - 68/13 -18/7
= 6 - 18/7
= 42/7 - 18/7
= 24/7
Cho A=34/7*13 + 51/13*22 + 85/22*37 + 68/37*49
B=39/7*16 + 65/16*31 + 52/31*43 + 26/43*49
Tìm tỉ số của A và B
Bài 1: Thực hiện phép tính:
a/ (–4).(+125).( –25).( –8).( –6) b/ 65 – 5 ( 13 + 7)
c/ 24. ( 16 – 5) – 16. ( 24 – 5) d/ 18 . 35 – 7. 5 . 8
e/ 31 . (– 18) – 31. ( – 81) – 31
Tính Nhanh:
a) 3 x 7 x 9 / 7 x 5 x 3
b)6 x 8 x 11/ 16 x 24
c) 15 x 12 x 7/ 14 x 25 x 18
d) 118 x 13 - 13 x 18/ 79 + 21
e) 111 + 111 x 63 - 14 x 111
f) 126 - 27 + 74 - 73/ 21 x 11 + 39 x 21
G)146 x 21 + 146 - 46 x 22/ 88 x 25
caau1:
a)58/19+13/17+35/43+119/19+8/43
b)-5/7*2/11+-5/7*9/11+13/4
c)146/13-(21/7+68/13
d)2/7*21/4-2/7*13/4
a) \(\frac{58}{19}+\frac{13}{17}+\frac{35}{43}+\frac{119}{19}+\frac{8}{43}\)
\(=\frac{13}{17}+\left(\frac{58}{19}+\frac{119}{19}\right)+\left(\frac{35}{43}+\frac{8}{43}\right)\)
\(=\frac{13}{17}+\frac{204}{19}+1\)
\(=\frac{1808}{133}\)
b) \(\frac{-5}{7}.\frac{2}{11}+\frac{-5}{7}.\frac{9}{11}+\frac{13}{4}\)
\(=\frac{-5}{7}.\left(\frac{2}{11}+\frac{9}{11}\right)+\frac{13}{4}\)
\(=\frac{-5}{7}.1+\frac{13}{4}\)
\(=\frac{71}{28}\)
c) \(\frac{146}{13}-\left(\frac{21}{7}+\frac{68}{13}\right)\)
\(=\left(\frac{164}{13}-\frac{68}{13}\right)+3\)
\(=\frac{135}{13}\)
d) \(\frac{2}{7}.\frac{21}{4}-\frac{2}{7}.\frac{13}{4}\)
\(=\frac{2}{7}.\left(\frac{21}{4}-\frac{13}{4}\right)\)
\(=\frac{2}{7}.\frac{8}{4}\)
\(=\frac{4}{7}\)
P/s: Mk ko chắc nữa!
caau1:
a)58/19+13/17+35/43+119/19+8/43
b)-5/7*2/11+-5/7*9/11+13/4
c)146/13-(21/7+68/13
d)2/7*21/4-2/7*13/4
b: \(=\dfrac{-5}{7}\left(\dfrac{2}{11}+\dfrac{9}{11}\right)+\dfrac{13}{4}=\dfrac{-5}{7}+\dfrac{13}{4}=\dfrac{-20+91}{28}=\dfrac{71}{28}\)
c: \(=\dfrac{146}{13}-3-\dfrac{68}{13}=6-3=3\)
d: \(=\dfrac{2}{7}\left(\dfrac{21}{4}-\dfrac{13}{4}\right)=\dfrac{4}{7}\)
A. BÀI TẬP.
I. Số nguyên:
Bài 1: Thực hiện phép tính:
a/ (–4).(+125).( –25).( –8).( –6) b/ 65 – 5 ( 13 + 7)
c/ 24. ( 16 – 5) – 16. ( 24 – 5) d/ 18 . 35 – 7. 5 . 8
e/ 31 . (– 18) – 31. ( – 81) – 31
Bài 2: Tìm x, biết:
a/ 3x – 5 = - 7 + 65 b/ –12 + 3(–x + 7) = – 18
c/ 24: (3x – 2) = – 3
tính = cách hợp lí
13/90+1/4+77/90
16/81+5/13+65/81+8/13
\(\frac{13}{90}\)+ \(\frac{1}{4}\)+ \(\frac{77}{90}\)
= \(\left(\frac{13}{90}+\frac{77}{90}\right)+\frac{1}{4}\)
= 1 + \(\frac{1}{4}\)
= \(\frac{5}{4}\)
a ) 13/90 + 1/4 + 77/90
= ( 13/90 + 77/90 ) + 1/4
= 90/90 + 1/4
= 1 + 1/4
= 5/4
b ) 16/81 + 5/13 + 65/ 81 + 8/13
= ( 16/81 + 65/81 ) + ( 5/13+8/13 )
= 81/81 + 13/13
= 1 + 1
= 2
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