4. Elena noticed that, nine years ago, her cousin Katie was twice as old as Elena was then,
Then Elena said, “In four years, I'll be as old as Katie is now!" If Elena is currently e years
old and Katie is k years old, which system of equations matches the story?

6.(q^9)^2 a. 2q^18 b. q^18 c. q^81 d. q^11 7.(6q^6)^-4 a. 6q^1296 b. 1296q^2 c. 1/1296q^24 d. 6q^-24 8. what is the value of 12x^-3 y^-1 for x = -1 and y = 5? a. -12/5 b.-10 c.-0 d.5/12 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

Lorne subtracted 6x3 – 2x + 3 from –3x3 + 5x2 + 4x – 7. use the drop-down menus to identify the steps lorne used to find the difference.

Acomputer store bought a program at a cost of $10 and sold it for $13. find the percent markup