Question 84 (xiii)
Simplify
(s2t+tq2)2−(2stq)2
We have, (s2t+tq2)2−(2stq)2 =(s2t)2+(tq2)2+2×s2t×tq2−4s2t2q2=s4t2+t2q4−2s2t2q2
Question 58 (58)9÷(58)4=(58)4
Question 84 (viii)
(ab−c)2+2abc
Question 84 (xii)
(pq−qr)2+4pq2r
Question 84 (x)
(b2−49)(b+7)+343