313-3.31+92
Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
bằng cách tính tổng các chữ số…
Các số chia hết cho 3 là: 231; 1872; 92313.
\(=\left(2.\left(2^3\right)^4.\left(3^3\right)^2+2^2.\left(2.3\right)^9\right):\left(2^{12}.\left(3^2\right)^3.31\right)\)
\(=\left(2^{13}.3^6+2^{11}.3^9\right):\left(2^{12}.3^6.31\right)\)
\(=\left[2^{11}.3^6\left(2^2+3^3\right)\right]:\left(2^{12}.3^6.31\right)\)
\(=\frac{2^{11}.3^6.31}{2^{12}.3^6.31}=\frac{1}{2}\)
Đưa về phân số:
\(=\frac{2.8^4.27^2+4.6^9}{2^{12}.9^3.31}\)
\(=\frac{2.\left(2^3\right)^4.\left(3^3\right)^2+2^2.\left(2.3\right)^9}{2^{12}.\left(3^2\right)^3.31}\)
\(=\frac{2.2^{3.4}.3^{3.2}+2^2.2^9.3^9}{2^{12}.3^{2.3}.31}\)
\(=\frac{2.2^{12}.3^6+2^{2+9}.3^9}{2^{12}.3^6.31}\)
\(=\frac{2^{1+12}.3^6+2^{11}.3^9}{2^{12}.3^6.31}\)
\(=\frac{2^{13}.3^6+2^{11}.3^9}{2^{12}.3^6.31}\)
\(=\frac{2^{11}.3^6\left(2^2+3^3\right)}{2^{12}.3^6.31}\)
\(=\frac{2^{11}.3^6.31}{2^{12}.3^6.31}=\frac{1}{2}\)
Em hiểu hơn ko?
\(313^5.299-313^6.36\)
\(=313^5.299-313^636\)
\(=313^5\left(299-313.36\right)\)
Ta có:
Ta có: \(299\equiv5\left(mod7\right)\)
\(313\equiv5\left(mod7\right)\)
\(36\equiv1\left(mod7\right)\)
=> \(299-313.36\equiv5-5.1=0\left(mod7\right)\)
=> \(299-313.36⋮7\)
=> \(313^5.299-313^6.36⋮7\)
\(123\left(324+213\right)-23\left(313+224\right)\)
\(=123.537-23.537\)
\(=537\left(123-23\right)\)
\(=537.100=53700\)
Ta có:
3135x299-313x6x36 = 3135x(299-313x36)=3135x(299-(299+14)x3
=3135x(299-299x36-14x36)
= 3135x(299(1-36)-14x36)
=3155x(35x299-14x36)
=3155x(7x5x299-7x2x36)
=3155x7x(5x299-2x36) chia hết cho 7
Vậy 313^5*299-313^6*36 chia hết cho 7
bn ơi **** cho mik ha
3135.299-3136.36 = 3135.(299-313.36) = 3135.(-10969)
Vì -10969 chia hết cho 7 => 3135.(-10969) chia hết cho 7 => 3135.299 - 3136.36
\(313^5\cdot299-313^6\)
\(=313^5\cdot299-313^5\cdot313\)
\(=313^5\cdot\left(299-313\right)\)
\(=313^5\cdot\left(-14\right)⋮7\)
3135.299 - 3136
= 3135.(299-313)
= 3135.(-14) = 3155.(-2).7 chia hết cho 7
= 401.69
=31\(^3\)-3.31+31.3
=31\(^3\)-0
=31\(^3\)
Học tốt