x+{x+1}+{x+12}+{x+23}+{x+77}+{x+88}+[x+99}=370
Tớ đang cần gấp
Tính nhẩm:
9 x 2
9 x 5
9 x 6
9 x 1
9 x 3
9 x 4
9 x 9
9 x 10
9 x 8
8 x 9
9 x 7
7 x 9
Tính theo cách hợp lí:
(12 + 77 + 34 + 23 + 88 + 45 + 55 + 66) x (45200 – 1808 x 25)
(12 + 77 + 34 + 23 + 88 + 45 + 55 + 66) x (45200 – 1808 x 25)
=(12 + 77 + 34 + 23 + 88 + 45 + 55 + 66) x (45200-45200)
=(12 + 77 + 34 + 23 + 88 + 45 + 55 + 66) x 0
=0
(12 + 77 + 34 + 23 + 88 + 45 + 55 + 66) x (45200 – 1808 x 25)
= (12 + 77 + 34 + 23 + 88 + 45 + 55 + 66) x (45200 – 45200 )
= (12 + 77 + 34 + 23 + 88 + 45 + 55 + 66) x 0
= 0
= [ (12+88) + (77+23) + (34+66) + (45+55) ] x ( 45200 - 45200 )
= [ 100 + 100 + 100 + 100 ] x 0
= 400
ĐÁP ÁN : 400
chung minh rang fx chia het cho gx voi fx x 99 x 88 x 77 ... x 11 1và g x x 9 x 8 ... x 1
chung minh rang fx chia het cho gx voi fx=x^99+x^88+x^77+...+x^11+1và g(x)=x^9+x^8+...+x+1
hình x+y+z biết
a)x=12,y=15,z= -27
b)x=32,y=23,z= -16
c)x=8,y=23,z=-17
các bn làm giúp mik mik đang cần gấp
(x-9)/55 + (x-10)/66 = (x-11)/77 + (x-12)/88
\(\dfrac{x-9}{55}+\dfrac{x-10}{66}=\dfrac{x-11}{77}+\dfrac{x-12}{88}\\ \Leftrightarrow\left(\dfrac{x-9}{55}+\dfrac{1}{11}\right)+\left(\dfrac{x-10}{66}+\dfrac{1}{11}\right)-\left(\dfrac{x-11}{77}+\dfrac{1}{11}\right)-\left(\dfrac{x-12}{88}+\dfrac{1}{11}\right)=0\)
\(\Leftrightarrow\left(\dfrac{x-9}{55}+\dfrac{5}{55}\right)+\left(\dfrac{x-10}{66}+\dfrac{6}{66}\right)-\left(\dfrac{x-11}{77}+\dfrac{7}{77}\right)-\left(\dfrac{x-12}{88}+\dfrac{8}{88}\right)=0\)
\(\Leftrightarrow\dfrac{x-4}{55}+\dfrac{x-4}{66}-\dfrac{x-4}{77}-\dfrac{x-4}{88}=0\)
\(\Leftrightarrow\left(x-4\right)\left(\dfrac{1}{55}+\dfrac{1}{66}-\dfrac{1}{77}-\dfrac{1}{88}\right)=0\\ \Leftrightarrow x=4\left(vì.\dfrac{1}{55}+\dfrac{1}{66}-\dfrac{1}{77}-\dfrac{1}{88}\ne0\right)\)
cho f(x)=x99+x88+x77+...+x11+1
cho g(x)=x9+x8+...+x+1
chứng minh f(x) chia hết g(x)
Ta có:
\(f\left(x\right)=x^{99}+x^{88}+x^{77}+...+x^{11}+1\)
\(f\left(x\right)=\left(x^{99}+x^{88}+x^{77}+...+x^{11}\right)+1\)
\(f\left(x\right)=\left[\left(x^9\right)^{11}+\left(x^8\right)^{11}+\left(x^7\right)^{11}+...+x^{11}\right]+1\)
Ta thấy:
\(\left(x^9\right)^{11}\) chia hết cho \(x^9\)
\(\left(x^8\right)^{11}\) chia hết cho \(x^8\)
\(..........\)
\(x^{11}\) chia hết cho \(x\)
\(1\) chia hết cho \(1\)
\(\Rightarrow f\left(x\right)\) chia hết cho \(g\left(x\right)\) ( Đpcm )
Tích sau tận cùng bằng mấy chữ số 0
20 x 21 x 22 x 23 x . . . x 99 x 100
Cứu mình với ,mình đang cần gấp !
(12+77+34+23+88+45+55+66)x(45200-1808x25)
Tính theo cách theo cách hợp lí
\(=\left[66+34+77+23+12+88+45+55\right]\times\left[1808\times\left(25-25\right)\right]\\ =0\)