Question

Daca a+b=33 si a+c=11,calculati 5.a+3.b+2.c

Answer 1

a + b = 33   si   a + c = 11

5 a + 3 b + 2 c = 121

= 2 a + 3 a + 3 b + 2 c =

= ( 3 a + 3 b ) + ( 2 a + 2 c ) =

= 3 ( a + b ) + 2 ( a + c ) =

= 3 × 33 + 2 × 11 =

= 99 + 22 =

= 121