Cory has a sister named Jessica. Jessica is 7 years older than twice Cory's age. Write an
expression that represents the relationship of
Jessica's age in terms of Cory's age, c.

2c+7

Step-by-step explanation:

Jessica is 7 more than 2x Cory's age.

Given that Cory is c years old,

then Jessica is

2c+7

I hope this helps! :)

reduce the friction between its moving parts

step-by-step explanation:

in fact, by reducing the friction between the moving parts of the machine, it is possible to reduce the energy wasted due to this friction; therefore, more input energy is converted into useful work, and this will improve the efficiency of the machine.

you didn't post any answer choices, so its not 100% clear what your teacher is looking for

however, log(15/7) is equivalent to log(15) - log(7)

i'm using the rule log(x/y) = log(x) - log(y)