Find the possible values of the constant
k, if the roots of the quadratic equation
x-(k+2)x+4=0 are equal.
8. if a and b are the roots of the quadratic
equation px' +qx+r=0, express
(2++b? ) in terms p, q andr.
if y = 2x - 3x - 1, find the minimum
value of y and the corresponding value
ofx.
10. given that y = 2 - 3x - 4x, find the
maximum value of y and the value of x
at which y is maximum.

pls answer no 7,9 and10