= 2 nha

bn vào câu hỏi tương tự đó

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

\(\frac{1.5.6+2.10.12+4.20.24+9.45.54}{1.3.5+2.6.10+4.20.12+9.27.45}=\frac{1.5.6+2^3.1.5.6+4^3.1.5.6+9^3.1.5.6}{1.3.5+2^3.1.3.5+4^3.1.3.5+9^3.1.3.5}=\frac{1.5.6.\left(1+2^3+4^3+9^3\right)}{1.3.5.\left(1+2^3+4^3+9^3\right)}=\frac{6}{3}=2\)

đáp số là 2

nhớ tích hộ tớ nhé

1/2+2/3+3/4+4/5+5/6+6/7+7/8+8/9+9/10x9/10

=9/10x(1/2+2/3)+(3/4+4/5)+(5/6+6/7)+(7/8+8/9)

=9/10x(1/3+3/5+5/7+7/9)

9/10x(1/3+3/5)+(5/7+7/9)

=9/10x1/5+5/9

9/50+5/9

=10

Bn Long làm đúng rồi bn   nguyễn kim arica cứ làm theo cách đó là được .

Bn nào thấy đúng thì ủng hộ nha .

A=(1+2+3+...+200) : (6+8+10+...+34)

A=\(\frac{\left[\left(200-1+1\right).\left(200+1\right)\right]}{2}:\frac{\left[\left(34-6\right):2+1\right].\left(34+6\right)}{2}\)

A=20100 : 300

A=67.

B=( 41x66+34x66):(3+7+11+...+79)

B=[(41+34).66]:\(\frac{\left[\left(79-3\right):4+1\right].\left(79+3\right)}{2}\)

B=(75.66):820

B=4950:820

B=\(\frac{495}{82}\)