Someone please help me?

Aheated piece of metal cools according to the function c(x) = (.5)x ? 7, where x is measured in hours. a device is added that aids in cooling according to the function h(x) = ? x ? 2. what will be the temperature of the metal after two hours?

What does x = in this equation x+3+2x=x+5

Which of the binomials below is a factor of this exression? 16x^2+40xy+25y^2 a.4x-5y b. 2x-5y c.4x+5y d.2x+5y