Question

D= 2x+3y+2017+3x+2y với x+y=12

Answer 1

D = 2x+3y+2017+3x+2y 

D = ( 2x + 3x ) + ( 3y + 2y) + 2017 

D = 5x + 5y + 2017

D = 5( x + y) + 2017

Thay ...

5. 12 + 2017 = 60 + 2017 = 2077

Vậy ....

Answer 2

D = 2x + 3y + 2017 + 3x +  2y 

D = (2x +  2y) + (3x + 3y) + 2017

D = 2(x + y) + 3(x + y) + 2017

D = 2 * 12 + 3 * 12 + 2017          (vì x + y =12)

D = 24 + 36 + 2017 = 2077