Question

a×b=30, a×c=18 calculati a×(a×c):16 si a×(b-c):4

Answer 1

ab=30
ac=18
_______ -
ab-ac=12
a(b-c)=12/:4
a (b-c)=3

Answer 2

a·b=30
a·c=18
$\frac{a(b-c)}{4}= \frac{ab-ac}{4}= \frac{30-18}{4}= \frac{12}{4} =3$