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\(S=\left(2.1\right)^2+\left(2.2\right)^2+\left(2.3\right)^2+....+\left(2.10\right)^2\)
\(\Rightarrow S=2^2.1^2+2^2.2^2+....+2^2.10^2\)
\(\Rightarrow S=2^2\left(1^2+2^3+3^2+.....+10^2\right)\)
Áp dụng giả thiết từ đề
\(\Rightarrow S=2^2.385\)
\(\Rightarrow S=4.384=1540\)
\(S=2^2+4^2+6^2+...+20^2\)
\(=1^2.4+2^2.4+3^2.4+...+10^2.4\)
\(=4.\left(1^2+2^2+3^2+...+10^2\right)\)
\(=4.385=1540\)
Vì 12+22+32+...+102 = 385
Mà S = 22+42+62+...+202
= 22.(12+22+32+...+102) = 4.385 = 1540
=1^2.2^2+2^2.2^2+2^2.3^2+...+2^2.10^2
=2^2.(1^2+2^2+3^2+4^2+...+10^2)
=2^2.385
tự tính nhé
Click vào câu hỏi tương không tự nhé bạn
S = 22 + 42 + 62 + ... + 202
S = 22 ( 12 + 22 + 32 + ... + 102 )
Vì 12 + 22 + 32 + ... + 102 = 385
=> S = 22 . 385
S = 4 . 385
S = 1540
Vậy S = 1540
Vì 2^2=2^2.1^2,4^2=2^2.2^2,....20^2=2^2.10^2
Suy ra S=2^2.(1^2+2^2+...+10^2)
Mà theo bài ra,phần dấu trong ngoặc bằng 385
Suy ra S=2^2.385=4.385=1540
Vậy S có giá trị bằng 1540
Ta có : \(2^2+4^2+6^2+...+20^2=\left(1\cdot2\right)^2+\left(2\cdot2\right)^2+\left(2\cdot3\right)^2+...+\left(2\cdot10\right)^2\)
\(=4\cdot1^2+4\cdot2^2+4\cdot3^2+...+4\cdot10^2\)
\(=4\left(1^2+2^2+3^2+...+10^2\right)\)
\(=4\cdot385=1540\)
Ta có: \(1^2+2^2+3^2+...+10^2=385\)
\(\Rightarrow2^2\left(1^2+2^2+3^2+...+10^2\right)=2^2.385\)
\(\Rightarrow2^2+4^2+6^2+...+20^2=1540\)
S=2^2+4^2+6^2+...+20^2
=(1.2)^2+(2.2)^2+(2.3)^2+...+(2.10)^2
=1^2.2^2+2^2.2^2+2^2.3^2+...+2^2.10^2
=2^2.(1^2+2^2+3^3+...+10^2)
=2^2.385=4.385=1540
đề có thiếu sót nhé,tớ sửa vào rồi đấy
Ta có: \(S=\left(1.2\right)^2+\left(2.2\right)^2+\left(3.2\right)^2+...+\left(10.2\right)^2\)
\(\Rightarrow S=1.2^2+2^2.2^2+3^2.2^2+..+10^2.2^2\)
\(\Rightarrow S=2^2\left(1+2^2+3^2+..+10^2\right)\)
\(\Rightarrow S=4.385=1540\)
ta có : S=\(\left(2.1\right)^2+\left(2.2\right)^2+\left(2.3\right)^2+..+\left(2.10\right)^2\)
=\(2^2\left(1^2+2^2+3^2+...+10^2\right)\)
=4.385 =1540
a) A=\(\frac{2^{13}.3^5-4^6.9^2}{\left(2^2.3\right)^6+8^4.3^5}-\frac{5^{10}.7^5-25^3.49^2}{\left(125.7\right)^3+5^9.14^3}\) =\(\frac{2^{13}.3^5-\left(2^2\right)^6.\left(3^2\right)^2}{\left(2^2\right)^6.3^6+\left(2^3\right)^4.3^5}-\frac{5^{10}.7^5-\left(5^2\right)^3.\left(7^2\right)^2}{\left(5^3\right)^3.7^3+5^9.\left(2.7\right)^3}\) =\(\frac{2^{13}.3^5-2^{12}.3^4}{2^{12}.3^6+2^{12}.3^5}-\frac{5^{10}.7^5-5^6.7^4}{5^9.7^3+5^9.2^3.7^3}\) =\(\frac{2^{12}.3^4.\left(2.3-1\right)}{2^{12}.3^5.\left(6+1\right)}-\frac{5^6.7^4.\left(5^4.7-1\right)}{2^3.5^9.7^3\left(1+1.2^3\right)}\) =\(\frac{2^{12}.3^4.5}{2^{12}.3^5.7}-\frac{5^6.7^4.4374}{3^3.5^9.7^3.9}\) =\(\frac{5}{3.7}-\frac{7.4374}{3^3.5^3.3^2}\) =\(\frac{5}{21}-\frac{7.4374}{3^6.5^3}\) =\(\frac{5}{21}-\frac{7.4374}{729.125}\) =\(\frac{5}{21}-\frac{42}{125}\) =\(\frac{-257}{2625}\) b)S=\(2^2+4^2+....+20^2\) =\(\left(1.2\right)^2+\left(2.2\right)^2+....+\left(10.2\right)^2\) =\(2^2.\left(2^2+4^2+....+10^2\right)\) =\(2^2.385\) =4.385 =\(1540\)
Ta có \(S=2^2+4^2+6^2+...+20^2\)
\(=4\left(1^2+2^2+3^2+...+10^2\right)\)
\(=4.385=1540\)
\(S=2^2+4^2+6^2+...+20^2\)
\(S=2^2.1^2+2^2.2^2+2^2.3^2+.....+2^2.10^2\)
\(S=2^2\left(1^2+2^2+3^2+....+10^2\right)\)
\(S=2^2.385=4.385=1540\)