\(4^{10}\times8^{15}\)

\(=\left(2^2\right)^{10}\times\left(2^3\right)^{15}\)

\(=2^{20}\times2^{45}\)

\(=2^{65}\)

\(4^{15}\times5^{30}\)

\(=\left(2^2\right)^{15}\times5^{30}\)

\(=2^{30}\times5^{30}\)

\(=\left(2\times5\right)^{30}\)

\(=10^{30}\)

\(27^{16}\div9^{10}\)

\(=\left(3^3\right)^{16}\div\left(3^2\right)^{10}\)

\(=3^{48}\div3^{20}\)

\(=3^{28}\)

4^10 . 8^15

= (2^2)^10 . (2^3)^15

= 2^20 . 2^45

= 2^20 + 45

= 2^65

4^15 . 5^30

= (2^2)^15 . 5^30

= 2^30 . 5^30

= 10^30

27^16 : 9^10

= (3^3)^16 : (3^2)^10

= 3^48 : 3^20

= 3^48 - 20

= 3^28

a:Sửa đề: 1x3+2x4+...+99x101

\(=1\times\left(1+2\right)+2\times\left(2+2\right)+\cdots+99\times\left(99+2\right)\)

\(=\left(1\times1+2\times2+\cdots+99\times99\right)+2\times\left(1+2+\cdots+99\right)\)

\(=\frac{99\times\left(99+1\right)\times\left(2\times99+1\right)}{6}+2\times\frac{99\times100}{2}\)

\(=\frac{99\times100\times199}{6}+99\times100=33\times50\times199+99\times100\)

\(=33\times50\times\left(199+3\times2\right)=33\times50\times205=338250\)

b: \(\frac89\times\frac{15}{16}\times\ldots\times\frac{2499}{2500}\)

\(=\left(1-\frac19\right)\times\left(1-\frac{1}{16}\right)\times\ldots\times\left(1-\frac{1}{2500}\right)\)

\(=\left(1-\frac13\right)\times\left(1-\frac14\right)\times\ldots\times\left(1-\frac{1}{50}\right)\times\left(1+\frac13\right)\times\left(1+\frac14\right)\times\ldots\times\left(1+\frac{1}{50}\right)\)

\(=\frac23\times\frac34\times\ldots\times\frac{49}{50}\times\frac43\times\frac54\times\ldots\times\frac{51}{50}=\frac{2}{50}\times\frac{51}{3}=\frac{17}{25}\)

Ai biết trả lời nhanh giúp mình nha mình đang cần luôn rất rất rất rất gấp.

mk chịu

Ai biết trả lời nhanh giúp mình mình kết bạn cùng

sorry bn nha bài này chịu 

\(x=\dfrac{3}{4}+\dfrac{8}{9}+\dfrac{15}{16}+...+\dfrac{99}{100}=\dfrac{1.3}{2^2}+\dfrac{2.4}{3^2}+\dfrac{3.5}{4^2}+...+\dfrac{9.11}{10^2}=\dfrac{1.2.3...9}{2.3.4...10}.\dfrac{3.4.5...11}{2.3.4...10}=\dfrac{1}{10}.\dfrac{11}{2}=\dfrac{11}{20}\)

\(\frac{3}{4}x\frac{8}{9}x\frac{15}{16}x...x\frac{99}{100}=\frac{1x3}{2x2}x\frac{2x4}{3x3}x\frac{3x5}{4x4}x...x\frac{9x11}{10x10}\)

\(=\frac{1x2x3x...x9}{2x3x4x...x10}x\frac{3x4x5x...x11}{2x3x4x...x10}\)

\(=\frac{1}{10}x\frac{11}{2}\)

\(=\frac{11}{20}\)

tớ cũng đang không biết phải giải thế nào