1x5x6+2x10x12+4x20x24+.....+9x45x54
1x3x5+2x6x10+4x12x20+.......+9x27x45
tính
A= 1x5x6+2x10x12+4x20x24+9x45x54
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1x3x5+2x6x10+4x12x20+9x27x45
Tính nhanh :
A = \(\frac{1x5x6+2x10x12+4x20x24+9x45x54}{1x3x5+2x6x10+4x12x20+9x7x45}\)
Ta có:
\(A=\frac{1x5x6+2x10x12+4x20x24+9x45x54}{1x3x5+2x6x10+4x12x20+9x27x45}\)
\(=\frac{1x3x5x2+2x6x10x2+4x12x20x2+9x27x45x2}{1x3x5+2x6x10+4x12x20+9x27x45}\)
\(=\frac{\left(x3x5+2x6x10+4x12x20+9x27x45\right)x2}{x3x5+2x6x10+4x12x20+9x27x45}\)
\(=2\)
\(A=\frac{1x5x6+1.2x2.5x2.6+1.4x4.5x6.4+1.9x5.9x6.9}{1x3x5+1.2x3.2x2.5+1.4x3.4x5.4+1.7x3.3x5.9}\)
\(A=\frac{1x5x6\left(1+2.2.2+4.4.4+9.9.9\right)}{1x3x5\left(1+2.2.2+4.4.4+7.3.9\right)}\)
\(A=\frac{1x5x6.802}{1x3x5.262}\)\(A=\frac{1x5x6.2.401}{1x3x5.2.131}\)
còn đâu cậu tự làm
Tính tổng:
1x5x6+2x10x12+20x24x4+9x45x54
1x3x5+2x6x10+4x12x20+9x27x45
#)Giải :
\(\frac{1x5x6+2x10x12+20x24x4+9x45x54}{1x3x5+2x6x10+4x12x20+9x27x45}\)
\(=\frac{24x54}{3x27}\)( loại các số giống nhau trên cả tử và mẫu )
\(=\frac{1296}{81}=16\)
#~Will~be~Pens~#
\(\frac{1\times5\times6+2\times10\times12+20\times24\times4+9\times45\times54}{1\times3\times5+2\times6\times10+4\times12\times20+9\times27\times45}\)
\(=\frac{1\times5\times2\times3+2\times10\times2\times6+20\times2\times12\times4+9\times45\times27\times2}{1\times3\times5+2\times6\times10+4\times12\times20+9\times27\times45}\)
\(=\frac{2+2+2+2}{1}=\frac{8}{1}=8\)
~ Hok tốt ~
tính nhanh
A= 1x5x6+2x10x12+4x20x24+9x45x54
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1x3x5+2x6x10+4x12x20+9x27x45
bài 8
cho S1=1+2;S2=3+4+5;S3=6+7+8+9;...... tính S100
bài 9
\(A=\frac{41x66+34x41}{3+7+11+....+79}\) \(B=\frac{1+2+3+4+....+200}{6+8+10+...+34}\)
\(C=\frac{1x5x6+2x10x12+4x20x24+9x45x54}{1x3x5+2x6x10+4x12x20+9x27x45}\)
ai nhanh nhất tớ tik
tinh nhanh
a=1x5x6+2x10x12+4x20x24+9x4554 / 1x3x5+26x10+4x20x12+9x27x45
\(\frac{1.5.6+2.10.12+4.20.24+9.45.54}{1.3.5+2.6.10+4.20.12+9.27.45}=\frac{1.5.6+2^3.1.5.6+4^3.1.5.6+9^3.1.5.6}{1.3.5+2^3.1.3.5+4^3.1.3.5+9^3.1.3.5}=\frac{1.5.6.\left(1+2^3+4^3+9^3\right)}{1.3.5.\left(1+2^3+4^3+9^3\right)}=\frac{6}{3}=2\)
đáp số là 2
nhớ tích hộ tớ nhé
A=\(\frac{1x5x6+2x10x12+24x8x10}{1x3x5+2x6x10+8x6x20}\)
\(A=\frac{1x5x6+2x1x2x5x2x6+8x1x2x5x4x6}{1x3x5+2x1x2x3x2x5+8x1x2x3x4x5}\)
\(A=\frac{1x5x6+2x2x2x1x5x6+8x2x4x1x5x6}{1x3x5+2x2x2x1x3x5+8x2x4x1x3x5}\)
\(A=\frac{1x5x6x\left(1+2x2x2+8x2x4\right)}{1x3x5x\left(1+2x2x2+8x2x4\right)}=\frac{6}{3}=2\)
(1x5x6+4x20x24):(1x3x5+4x12x24)
tính nhanh hộ mình ạ, ko dc thì tính thường
TÍNH NHANH: 1X5X6+2X10X12+3X20X24+...+9X45X54