Verify the following: (a) 18 ×[7+(-3)] = [18 × 7] + [18 × (-3)] (b) (-21) ×[(-4)+(-6)] = [(-21) ×(-4)] + [(-21) ×(-6)]

Question

Verify the following: (a) 18 &#xD7;[7+(-3)] = [18 &#xD7; 7] + [18 &#xD7; (-3)] (b) (-21) &#xD7;[(-4)+(-6)] = [(-21) &#xD7;(-4)] + [(-21) &#xD7;(-6)]

Philoid · Accepted Answer

(a) We have,

L.H.S = 18 × [7 + (- 3)]

= 18 × [7 – 3]

= 18 × [4]

= 72

Also, we have:

R.H.S = [18 × 7] + [18 × (-3)]

= 126 + (-54)

= 72

Therefore,

L.H.S = R.H.S

Hence,

18 × [7 + (- 3)] = [18 × 7] + [18 × (-3)]

_{(b) We have,}

_{L.H.S = (-21) × [(-4) + (-6)]}

_{= (-21) × [- 4 – 6]}

_{= (-21) × (-10)}

_{= 210}

_{Also, we have:}

_{L.H.S = [(-21) × (-4) + [(-21) × (-6)]}

_{= 84 + 126}

_{= 210}

_{Also, we have:}

_{R.H.S = [(-21) × (-4)] + [(-21) × (-6)]}

_{= 84 + 126}

_{= 210}

_Therefore,

_{L.H.S = R.H.S}

_Hence,

_{[(-21) × (-4) + [(-21) × (-6)] = [(-21) × (-4)] + [(-21) × (-6)]}