The difference of a number and seven is twelve

Write an equation to represent the sentence

If there is no real number solution to the quadratic equation x^2+2x+c=0 what is a possible value of c? 1 -2 0 3

Simplify the expression and find the missing terms. the simplest form of has in the numerator and in the denominator.

Tom can paint the fence in 12 hours, but if he works together with a friend they can finish the job in 8 hours. how long would it take for his friend to paint this fence alone?