Question

Daca a+b=3,2 și b+c=5,3, calculați :
a)4a+5b+c
b)2a+7b+5c
c)3a+10b+7c
d)10a+12b+2c.
Ofer 15 puncte.

Answer 1

a)4a+5b+c=
4a+4b+b+c=
4(a+b)+(b+c)
4x3,2+5,3=
12,8+5,3=18,1

b)2a+7b+5c=
2a+2b+5b+5c=
2(a+b)+5(b+c)
2x3,2+5x5,3=
6,4+26,5=32,9

c)3a+10b+7c=
3a+3b+7b+7c=
3(a+b)+7(b+c)
3x3,2+7x5,3=
9,6+37,10=46,7

d)10a+12b+2c=
10a+10b+2b+2c=
10(a+b)+2(b+c)
10x3,2+2x5,3=
32+10,6=42,6