Find:

Question

Two numbers whose sum -10 and whose product is 5.
;;; x+y = -10 x= -10-y xy=5
(-10-y)y=5 -10y-y^2 = 5
-y^2-10y-5=0
y= -9.47213595499958 and
y= -0.52786404500042
Two numbers whose sum is 1 and whose product is 1.
;;; y= (-1+ sqrt(-3))/-2
y= (-1 - sqrt(-3))/-2

Find the dimensions of a rectangle whose area is 60 cm2 and whose perimeter is 200 cm.

Answer 1

your given solutions are correct. As for the last one,

x+y=100, so
x(100-x)=60
...