Problem: Let r be the result of doubling both the base and the exponent of ab,bî€ =0. If r equals the product of ab by xb, then x equals:
Answer Choices:
A. a
B. 2a
C. 4a
D. 2
E. 4
Solution:
r=(2a)2b=((2a)2)b=(4a2)b; also r=abâ‹…xb =(ax)b therefore(ax)b=(4a2)b therefore ax=4a2 therefore x=4a