Ta có : 5 + 52 + 53 + ........... + 58
= ( 5 + 52 ) + 52 ( 5 + 52 ) + ............ + 56 ( 5 + 52 )
= 30 + 52 * 30 + ............. + 56 * 30
= 30 ( 1 + 52 + ........... + 56 ) chia hết cho 30
=> 5 + 52 + 53 + ............. + 58 là bội của 30
chung to rang gia tri cua bieu thuc A=5+52+53+.....+58 la boi cua 30
chung to rang voi moi so tu nhien N gia tri cua 2 bieu thuc 7n+10 va 5n+7 luon la 2 so nguyen to cung nhau
a) tim gia tri nho nhat cua bieu thuc : A = | 1-x | + 8
b) tim cac so nguyen x biet 13 la boi cua x - 4
c) tim so nguyen x sao cho ( x + 5 ) chia het cho ( x + 3 )
giup minh voi! minh can gap gap gap.....
cho bieu thuc a^3+2a^2-1/a^3+2a^2+2a+1
a) Rut gon bieu thuc
b)Chung minh rang neu a la so nguyen thi gia tri tim duoc cua bieu thuc o cau a) la 1 phan so toi gian
Cho bieu thuc A = a3 + 2a2 - 1 / a3 + 2a2 + 2a + 1
a) Rut gon bieu thuc
b) Chung minh rang neu a la so nguyen thi gia tri cua bieu thuc tim duoc cua cau a la mot phan so toi gian.
\(A=\frac{a^3+2a^2-1}{a^3+2a^2+2a+1}\)
a)rut gon bieu thuc
b)chung minh rang neu a la so nguyen thi gia tri cua bieu thuc tim duoc cua cau a la mot phan so toi gian
cho bieu thuc A =\(\frac{a^3+2a^2-1}{a^3+2a^2+2a+1}\)
a)rut gon bieu thuc
b)chung minh rang neu a la so nguyen thi gia tri cua bieu thuc tim duoc o cau a la mot phan so toi gian
thấy dau sao (.) biểu thức
1*2*3*4*5*6*7*8*9 boi cac dau cong tru de gia tri cua bieu thuc =
a)-13 b)-4
Chung minh rang : 5 + 52 + 53 + ... + 58 la boi cua 30
