In which expression should the exponents be multiplied
a.2^9 over 2^7
b.(6^10)^-7
c.(1 over 2)^3 (1 over 2)^5
d.5^2 . 5^4

Aclass consists of 55% boys and 45% girls. it is observed that 25% of the class are boys and scored an a on the test, and 35% of the class are girls and scored an a on the test. if a student is chosen at random and is found to be a girl, the probability that the student scored an ais

Write 5(6x+4)-2(5x-2) in the form a(bx+c) where a,b and c integers and a> 1

X/y + 4y/x divided by x/y - 2y/x explain as in depth as you can how you simplfied the fractions. i don't know where to start on this : /