Question 85 (a)
Evaluate 78×a10b7c1276×a8b4c12
We have 78×a10b7c1276×a8b4c12=(7876)×(a10a8)×(b7b4)×(c12c12)=78−6×a10−a×b7−4×c12−12=72×a2×b3×c0=49a2b2
Question 85 (c)
Evaluate 125×52×a7103×a4