Question

Tìm x biết x + 2x + 3x + ⋯ + 10x = -165.

Answer 1

Ta có:

 x + 2x + 3x + ⋯ + 10x = -165.

x.(1+2+3+.....+10)=-165

x.55=-165

x=-165:55

x=-3

Vậy x=-3

Answer 2

tong tren co 10 so hang , ta co : 

    10x + (1+2+3+......+8+9+10)=-165

10x + 55 = -165

10x = -165 +55

10x =  -110

x = -110 : 10 

x = -11

tich minh nha ban oi , thanks

 

 

Answer 3

minh lam nham ban oi , x = -3 , tich nha , thanks

Answer 4

x + 2x + 3x + ... + 10x = -165

=> x * ( 1 + 2 + 3+ ... +10 ) = -165

=> x * 55 = -165

=> x = -165 / 55

=> x = -3

NHA CÁC BN

Answer 5

x+2x+3x+...+10x=-165

x(1+2+3+...+10)=-165

55x=-165

x=-3