0,24 x 450 + 0,8 x 15 x 3 + 3 x 3 x 8

= 0,24 x 450 + 0,24 x 150 + 0,24 x 300

= 0,24 x ( 450 + 150 + 300 )

= 0,24 x 900

= 216

Toán lớp 5 dễ mà ! Thui ! ~ nyan ! Bây giờ T-I-C-H cho mik nhá !!!!

0.24*150*3+0.8*15*3+3*3*8=3(36+7.5+24)=3*67.5=202.5

=0,24 x 450 + 0,08  x 3 x 15 x 10 + 0,03 x 8 x 3 x100 

=0,24 x 450 + 0,24 x 150 + 0,24 x 300

=0,24 x ( 450+150+300)

=0,24x900

=216 

a)1/2:0,5-1/4:0,25+1/8:0,125-1/10:0,1

=1/2x2-1/4x4+1/8x8-1/10x10

=1-1+1-1

=0

b)không biết k 2 cái là dc rồi

${}^{}{}^{}-\left({}^{}-1\right)\left({}^{}+1\right)$

$={}^{}-\left({}^{}-1\right)$

$={}^{}-{}^{}+1=1$

\(3^8.5^8-\left(15^4-1\right)\left(15^4+1\right)\)

\(=15^8-\left[\left(15^4\right)^2-1^2\right]\)

\(=15^8-\left[15^8-1\right]\)

\(=15^8-15^8+1=1\)

3⁸ x 5⁸ - ( 15⁴-1 ) . ( 15⁴ +1 )

= 15⁸ - ( 15⁸ - 1 )

= 15⁸ - 15⁸ + 1

= 1

0,24 x 450 + 0,8 x 15 x 3 + 3 x 4 x8

=0,24 x 100 x 4,5 + 0,8 x 3 x 15 + 3 x 8 x 4

=24 x 4,5 + 2,4 x 10 x 1,5 + 24 x 4

=24 x 4,5 + 24 x 1,5 + 24 x 4

=24 x (4,5 + 1,5 + 4)=24 x 10 = 240

0,24 x 450 + 0,8 x 15 x 3 + 3 x 4 x 8

= 0,24 x 100 x 45 + 0,8 x 3 x 15 + 3 x 8 x 4

= 24 x 4,5 + 2,4 x 15 + 24 x 4

= 24 x 4,5 + 24 x 1,5 + 24 x 4

= 24 x ( 4,5 + 1,5 + 4 )

= 24 x 10 = 240

ai giai ho minh bai toan nay thi minh h cho

0.24x450+0.8x15x3+3x3x8

=2x2/1x3 x 3x3/2x4x4/3x5 x ... x 11x11/10x12

=2x2x3x3x4x4x...x11x11/1x3x2x4x3x5x...x10x12

= 2x3x4x...x11)x(2x3x4x...x11)/(1x2x3x4x...x11)/(1x2x3x...x10)x(2x3x4x...x11)

=11x2/1x12

=22/12

=11/6

4/3x9/8x16/15x...x121/120=\(\dfrac{2^2}{1\cdot3}\)x\(\dfrac{3^2}{2\cdot4}\)x\(\dfrac{4^2}{3\cdot5}\)x...x\(\dfrac{11^2}{10\cdot12}\)=\(\dfrac{2}{3}\)x\(\dfrac{11}{10}\)=\(\dfrac{11}{15}\)

4/3x9/8x16/15x...x121/120=\(\dfrac{2^2}{1\cdot3}\)x\(\dfrac{3^2}{2\cdot4}\)x...x\(\dfrac{11^2}{10\cdot12}\)=\(\dfrac{2}{3}\)x\(\dfrac{11}{10}\)=\(\dfrac{11}{15}\)

Đặt \(A=\frac{1.2+2.4+3.6+4.8+5.10}{4+6.8+9.12+12.16+15.20}\)

\(\Rightarrow A=\frac{1.\left(1+2\right)+2.\left(1+2\right)+3.\left(1+2\right)+4.\left(1+2\right)+5.\left(1+2\right)}{4+2.\left(3+4\right)+3.\left(3+4\right)+4.\left(3+4\right)+5.\left(3+4\right)}\)

\(\Rightarrow A=\frac{\left(1+2+3+4+5\right).\left(1+2\right)}{4+\left(2+3+4+5\right).\left(3+4\right)}\)

\(\Rightarrow A=\frac{\left(1+5\right).5:2.\left(1+2\right)}{4+\left(2+5\right).4:2.\left(3+4\right)}\)

\(\Rightarrow A=\frac{6.5:2.3}{4+7.4:2.7}=\frac{45}{4+98}=\frac{45}{102}=\frac{15}{34}\)

Vậy \(A=\frac{15}{34}\)

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