14 students should have red hair, if that's what you're asking.
I am assuming you wrote the problem wrong. Is it a^2?
A^2 -4A-21=0
(A-7)(A+3)=0
A=7 A=-3, ignore the negative number because it doesn't make sense if you plug in for a.
length=a+3=7+3=10
Width=7=a
-40 i think.............. im not positive but i did my best
Answer:
3
Step-by-step explanation:
The equation of a parabola in vertex form is
y = a(x - h)² + k
where (h, k) are the coordinates of the vertex and a is a multiplier
Here (h, k) = (2, - 4) , thus
y = a(x - 2)² - 4
To find a substitute (3, - 1 ) into the equation
- 1 = a(3 - 2)² - 4 ( add 4 to both sides )
3 = a
Thus
y = 3(x - 2)2 - 4 ← equation in vertex form
= 3(x² - 4x + 4) + 4
= 3x² - 12x + 12 + 4
= 3x² - 12x + 16 ← equation in standard form
with coefficient of x² term = 3
