Question

Check the following for equality. 

(i) (11 + 7) + 10 and 11 + (7 + 10) 

(ii) (8 – 13) x 7 and 8 – (13 x 7) 

(iii) [(-6) – (+8)] x (-4) and (-6) – [8 x (-4)] 

(iv) 3 x [(-4) + (-10)] and [3 x (-4) + 3 x (-10)]

Answer 1

(i) LHS = (11 + 7) + 10 = 18 + 10 = 28 

RHS = 11 + (7 + 10) 

= 11 + (17) = 28 

LHS = RHS

∴ (11 + 7) + 10 = 11 + (7 + 10)

(ii) LHS = (8 – 13) x 7 = -5 x 7 = -35 

RHS = 8 – (13 x 7) = 8 – 91 = -83 

LHS ≠ RHS 

∴ (8 – 13) x 7 ≠ 8 – (13 x 7)

(iii) LHS = [(-6) – (+8)] x (-4) = [(-6) + (-8)] x (-4) 

= (-14) x (-4) = +56 

RHS = (-6) – [8 x (-4)] = -6 – (-32) 

= -6 + (+32) = +26 

LHS ≠ RHS 

∴ [(-6) – (+8)] x (-4) ≠ (-6) – [8 x (-4)]

(iv) LHS = 3 x [(-4) + (-10)] = 3 x (-14) = -42 

RHS = [3 x (-4) + 3 x (-10)] = (-12) + (-30) = -42

LHS = RHS 

3 x [(-4) + (-10)] = [3 x (-4) + 3 x (-10)]