Question

Daca a+b=7 , iar b+c=10, aflati a+3b+2c.

Answer 1

$a+3b+2c=a+b+b+b+c+c=a+b+b+c+b+c=7+10+10$=27

Answer 2

a+b=7 ; b+c=10|.2=> 2b+2c=20 adunand membru cu membru=>
=>(a+b)+(2b+2c)=7+20=> a+3b+2c=27