I need to determine if the following equation/función is linear ?

If c(x) = 4x – 2 and d(x) = x2 + 5x, what is (cxd)(x)

2. explain in words how you plot the point (4, −2) in a rectangular coordinate system.

Ftara spends $219 a month for her car payment and she makes $3,200 a month, what percent of her monthly income is spent on her car payment?