Express the ratio as a fraction in simplest form. 10 yards to 10 feet

The difference of 2 numbers is 21 and the quotient of the equation is 4 then what are the two numbers?

9. (y^-5)^10y^10 a. y^-60 b. y^60 c. y^-150 d. y^150 find the simplified form of each expression. 10. (4/7^5)^2 a.8/14^10 b.16/49^25 c.16/49y^10 d.8/14y^25 11. determine if the number 3.43 times 10^-6 is written in scientific notation. if not, explain. a. yes; the number is written scientific notation. b. no; the first factor is not a number between 1 and 10. c. no; it is not written as a number times a power of 10

What is the value of x in the equation (2)3) (x+6)= -18 a. -36 b. -33 c. -24 d. -18