Question

Folosind metoda factorului comun , calculeaza :
a) a x c-c x b daca a-b= 24 si c= 3
b) 7 x a +9 x b +2 x c si b+c=15

Answer 1

a)
a-b=24
c=3

a×c-c×b=c(a-b)=3×24=72

b)
b+c=15
a+b=43

7×a+9×b+2×c=
=7×a+7×b+2×b+2×c=
=7(a+b)+2(b+c)=
=7×43+2×15=
=301+30=
=331

Answer 2

ac-cb=c(a-b)=3x24=72

7a+9b+2c=7a+7b+2b+2c=
7(a+b)+2(b+c)=
7x43+2x15=
301+30=331