Question

2+4+6+8+...+2x=1056 hãy tìm x

trả lời giúp mình nhé

 

Answer 1

2 + 4 + 6 + 8 + ... + 2x = 1056

=> ( 2x + 2 ) . [( 2x - 2 ) : 2 + 1 ] : 2 = 1056

=> 2(x + 1 ) . ( x - 1 + 1 ) = 1056 . 2 = 2112

=> 2( x + 1 ) . x = 2112

=> (x + 1 ) . x = 1056

=> ( x + 1 ) . x = 33 . 32

=. x = 32

Vậy x = 32