tìm E biết:
E=6^1+6^3+6^5+6^7+...+6^99
1+2+3+4+5+6+7+8+9+.............+99=X+1+2+3+4+5+6+7+8+9+........................+99
Tìm X
1+2+3+4+5+6+7+8+9+...........+99=X+1+2+3+4+5+6+7+8+9+.................+99
4950=4950+X
X=4950-4950
X=0
Đọc sơ qua cái đề thì ai chả là X = 0
A=2 3/10-75%-1/4+0,7
B=20%+5 1/2+40%
C=0,202×16×12,5×50
D=6/1×3+6/3×5+6/5×7+....+6/95×97+6/97×99
E=0,33+0,38+0,67+12%
F=1,45×36+1,45×64/60×3,6-40×5,4+145×5
Mai mình phải nộp bài nên nhanh giúp mình ạ😅
1+1+2+2+2+3+3+3+4+4+4+5+5+5+6+6+6+7+7+...+99+99+100
1+1+2+2+2+3+3+3+3+4+4+4+5+5+5+6+6+6+7+7+7+...+99+99+99+100
= (1x2)+(2x3)+(3x3)+(4x3)+(5x3)+(6x3)+(7x3)+...+(99x3)+100
=2x6x9x12x15x18x21x...x297+100
=(297-2) : 3 + 1 +100
ok , phần còn lại tự tính nha bạn
d] D=6/3*5+6/5*7+...+6/97*99
e] E=1/2*5+1/5*8+1/8*11+1/17*20
g] G=5/2*1+4/1*11+3/11*2+1/2*15+13/15*4
Trần Thành Minh có giỏi thì làm câu g đi
Tính:
a,B=1+6^2+6^4+...+6^2016
b,C=2+2^3+2^5+...+2^2017
c,D=1-7+7^2-7^3+...-7^99+7^100
d,E=100^2-99^2+98^2_97^2+...+2^2-1^2
bài 1
A=1*2*3+2*3*4+3*4*5+...+99*100*101
B=1*3*5+3*5*7+...+95*97*99
C=2*4+4*6+..+98*100
D=1*2+3*4+5*6+...+99*100
E=1^2+2^2+3^2+...+100^2
G=1*3+2*4+3*5+4*6+...+99*101+100*102
H=1*2^2+2*3^2+3*4^2+...+99*100^2
I=1*2*3+3*4*5+5*6*7+7*8*9+...+98*99*100
K=1^2+3^2+5^2+...+99^2
A = 1*2*3 + 2*3*4 + 3*4*5 ... + 99*100*101
=> 4A = 1*2*3*4 + 2*3*4*4 + 3*4*5*4 + ... +99*100*101*4
=> 4A = 1*2*3*4 + 2*3*4*(5 - 1) + 3*4*5*( 6 - 2) + ... + 99*100*101*(102 - 98)
=> 4A = 1*2*3*4 + 2*3*4*5 - 1*2*3*4 + 3*4*5*6 - 2*3*4*5 + ... + 99*100*101*102 - 98*99*100*101
=> 4A = 99*100*101*102
=> 4A = 101989800
=> A = 25497450
A=6/1*3+6/3*5+6/5*7+.....+6/99*101
D = 1 - 6 + 11 - 16 + ... + 111
F = 2^100 - 2^99 - 2^98 - ...- 2^2 - 2 - 1
E = 1 + 2 - 3 -4 +5 + 6 - 7 - 8 +....+ 249 + 250
H = 1 -2 -3 -4 - 5 -6 - ... -97 - 98 - 99 - 100