Question

[kocoten]

(3a+2b-1)(a+5)-2b(a-2)=(3a+5)(a+3)+2(7b-10)

Answer 1

[l҉o҉n҉g҉ d҉z҉]

Chứng minh hả ? -.-

( 3a + 2b - 1 )( a + 5 ) - 2b( a - 2 ) = ( 3a + 5 )( a + 3 ) + 2( 7b - 10 )

<=> 3a² + 15a + 2ab + 10b - a - 5 - 2ab + 4b = 3a² + 14a + 15 + 14b - 10

<=> 3a² + 14a + 14b - 5 = 3a² + 14a + 14b - 5

=> đpcm