Question

(x+1)+(x+2)+(x+3)+...+(x+100)=5750

Answer 1

(x + 1) + (x + 2) + (x + 3) + ... + (x + 100) = 5750

(x + x + x + ... + x) + (1 + 2 + 3 + ... + 100) = 5750

    100 số x                          100 số

100x + (1 + 100) × 100 : 2 = 5750

100x + 101 × 50 = 5750

100x + 5050 = 5750

100x = 5750 - 5050

100x = 700

x = 700 : 100

x = 7

Vậy x = 7

Answer 2

(x + 1) + (x + 2) + (x + 3) + ... + (x + 100) = 5750

(x + x + x + ... + x) + (1 + 2 + 3 + ... + 100) = 5750

    100 số x                          100 số

100x + (1 + 100) × 100 : 2 = 5750

100x + 101 × 50 = 5750

100x + 5050 = 5750

100x = 5750 - 5050

100x = 700

x = 700 : 100

x = 7

Vậy x = 7