Question

(x+1)+(x+2)+(x+3)+(x+5)+...+(x+89)=571

Tính hợp lý

 

Answer 1

(x + 1) + (x + 2) + (x + 3) + ...+ (x + 89) = 571

=> 89x + (1 + 2 + 3 + ... + 89) = 571

=> 89x + 4005 = 571

=> 89x = -3434

=> x = -3434/89

Answer 2

(x + 1) + (x + 2) + (x + 3) + ...+ (x + 89) = 571

=> 89x + (1 + 2 + 3 + ... + 89) = 571

=> 89x + 4005 = 571

=> 89x = -3434

=> x = -3434/89