Question

Verify the following:
(a) $18\times [7+(-3\left)\right]=[18\times 7]+[18\times (-3\left)\right]$
(b) $(-21)\times \left[\right(-4)+(-6\left)\right]=\left[\right(-21)\times (-4\left)\right]+\left[\right(-21)\times (-6\left)\right]$

Answer 1

(a) LHS $=18\times [7+(-3)]=18\times 4=72$

RHS $=[18\times 7]+[18\times (-3)]$ $=126+(-54)=72$ (verified)

(b) LHS $=(-21)\times [(-4)+(-6)]=(-21)\times (-10)=210$

RHS $=[(-21)\times (-4)]+[(-21)\times (-6)]=84+126=210$ (verified)