Hello!
The discriminant of quadratic functions is: b² - 4ac. Since the equation is in standard form, which is Ax² + Bx + C = 0 , we can substitute those values into our discriminant and simplify.
The value of the discriminant will tell us how many solutions there are to the given quadratic equation.
A positive discriminant will have two real solutions.
A discriminant of zero will have one real solution.
A negative discriminant will no real solutions.
1. Substitute, a = 16, b = 8, c = 1.
8² - 4(16)(1)
64 - 4(16)(1)
64 - 64(1)
64 - 64
0
Since the discriminant is zero, the answer is choice A, double root, because since it is raised to the power of 2, it must has two roots, but in this case, both of the roots the same x-values.
<em>f(d)=86,400·d</em>
if you set 1 day (d=1) you get f(1)=86,400 sec
if you set 1 day (d=2) you get f(2)=172,800 sec
...etc.
So if you distribute 4 in the first parentheses, you get 12x+20y+8z.
Then you distribute 3 in the second parentheses. You'll get 3x-3z. That all equals 12x+20y+8z+3x-3z.
Now you have to start combining numbers with the same variable. Start with x. 12x+3x is 15x.
y has no other common variable, it's left alone.
8z-3z is 5z
All together now with the numbers in simpler form, the equation is 15x+20y+5z
Jenna's would be the right answer because when you distribute 5 in her answer you get 15x+20y+5z
