Answer: The piezoelectric effect describes the property of certain solids to generate an electrical charge under mechanical stress. The actuating force modifies the microscopic structure of the body; dipoles are created between which a voltage builds up. And Their positive and negative charges complement each other creating two types of electricity: static electricity
Explanation:
factorise 1/10^2 out of both.
add 1/4.5 to 1/9.4 .... common denominator 4.5x9.4
multiply result by 1/10^2
find reciprocal of result
phew !