Let the numbers be x and y. Then xy = -30 and x+y = -3.
Solve xy = -30 for y: y = -30/x
subst. -30/x for y in x+y= -3: x - 30/x = -3
Multiply all 3 terms by x: x^2 - 30 = -3x, so x^2 + 3x - 10 = 0
Solve this quadratic equation for x. x: {-5, 2}
If x = -5, then x+y = -3 becomes -5 + y = -3, and y = 2.
You should check to determine whether x=2 is also correct. If it is, what is the corresponding y value?
0.15 is bigger, this is because the 0.05 in 0.15 has more value than 0.02 in 0.125, even though it has a third digit.
X^2-11x+28=0
(x-7)(x-4)=0
x-7=0
x=7
x-4=0
x=4
The formula for the volume of a cone is
v = ( 1 / 3) h pi r^2
where h is the height of the cone
pi is 3.1416
r is the radius of the cone
since diameter is given
D = 2r
r = D/2 = 4/2 = 2 in
substitute the given
V = (1/3) (6) (3.1416) (2^2)
V = 25.1 cubic in