Tinh hợp lý
a) 2.5.25.4
b) 125.2.8.13
c) 83.14+27.17+83.13
d)72.11+23.72+72.66
Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
\(=36.54+23.72\)
\(=36.2.27+23.72\)
\(=72.27+23.72\)
\(=72\left(27+23\right)\)
\(=72.50=3600\)
a.165-65:5+28*3=165-13+84=152+84=236
b.(315:5+47)*2+21=(63+47)*2+21
=110*2+21
=220+21
=241
Hok tot.
a, 165 - 65 : 5 + 28 x 3
= 165 - 13 + 84
= 236
b, ( 315 : 5 + 47 ) x 2 + 21
= 110 x 2 + 21
= 241
A = 1/90 - 1/72 - 1/56 - ... - 1/6 - 1/2
A = 1/90 - (1/2 + 1/6 + ... + 1/56 + 1/72)
A = 1/90 - (1/1.2 + 1/2.3 + ... + 1/7.8 + 1/8.9)
A = 1/90 - (1 - 1/2 + 1/2 - 1/3 + ... + 1/7 - 1/8 + 1/8 - 1/9)
A = 1/90 - (1 - 1/9)
A = 1/90 - 8/9
A = 1/90 - 80/90
A = -79/90
A = 1/90 - 1/72 - 1/56 - ... - 1/6 - 1/2
A = 1/90 - (1/2 + 1/6 + ... + 1/56 + 1/72)
A = 1/90 - (1/1.2 + 1/2.3 + ... + 1/7.8 + 1/8.9)
A = 1/90 - (1 - 1/2 + 1/2 - 1/3 + ... + 1/7 - 1/8 + 1/8 - 1/9)
A = 1/90 - (1 - 1/9)
A = 1/90 - 8/9
A = 1/90 - 80/90
A = -79/90
d: A={-4;-3;-2;-1;0;1}
Tổng là: (-4)+(-3)+(-2)+(-1+1)+0=-9
\(a,2.5.25.4\) \(b,125.2.8.13\)
\(=\left(2.5\right).\left(25.4\right)\) \(=\left(125.8\right).\left(2.13\right)\)
\(=10.100\) \(=1000.26\)
\(=1000\) \(=26000\)
\(c,83.14+27.17+83.13\) \(d,72.11+23.72+72.66\)
\(=83.\left(14+13\right)+27.17\) \(=72.\left(11+23+66\right)\)
\(=83.27+27.17\) \(=72.100\)
\(=27.\left(83+17\right)\) \(=7200\)
\(=27.100\)
\(=2700\)
a) 2x5 x 25x4 = (2x5) x (25x4)
= 10 x 100
= 1000
b) 125x2x8x13 = (125x8) x 2x13
= 1000 x 36
= 36000
c) 83x14+27x17+83x13 = 83 x (14+13) + 27 x 17
= 83 x 27 + 27x17
= (83+17) x 27
= 100 x 27
= 2700
d) 72x11 + 23x72 + 72x66 = (11+23+66) x 72
= 100 x 72
= 7200