Question

Tìm x, biết:

a) ( x-1) x ( x-2) = 0

b) ( x+1) + ( x+2) + ... + ( x+100) = 9050

Answer 1

a) ( x - 1 ) ( x - 2 ) = 0

=> x - 1 = 0 hoặc x - 2 = 0

x - 1 = 0                                                       x - 2 = 0

x = 0 + 1 = 1                                                x = 0 + 2 = 2

Vậy x = 1 hoặc x = 2

b) ( x + 1 ) + ( x + 2 ) + ... + ( x + 100 ) = 9050

( x + x + ... + x ) + ( 1 + 2 + ... + 100 ) = 9050

=> 100x  + 5050 = 9050

100x = 9050 - 5050

100x = 4000

x = 4000 : 100 

x = 40