7 and -3 are the roots of the quadratic equation x^2+kx-21=0 what is the value of k

Koji is installing a rectangular window in an office building. the window is 823 feet wide and 534 feet high. the formula for the area of a rectangle is a=bh. what is the area of the window? enter your answer as a mixed number in simplest form in the box. $$ ft2

Which fraction is equal to 1hole and 2/5? a.3/5 b.75 c.57 d.73

If sin(x) = 0 and cos(x) = 1, what is tan(x)?