Hello,
Part A:

Part B:
x² coefficient is 4 >0 thus a minimun
as y=4(x+1)²-9 : vertex is (-1,-9)
Proof: see picture
Sorry for Part c: I don't know
In France, we make an array of (x,f(x)) and then plot the severals points.
Answer:
acute
Step-by-step explanation:
obtuse is over 90°
acute I less that 90°
and right is exactly 90°
Answer:
Answer : 52 girls
Step-by-step explanation:
Your ratio of boys to girls is 3:4
Set up a fractional proportion and cross multiply
3/4 = 39/x
cross multiply
3x = 4(39)
3x = 156
x = 156/3
x = 52 girls
Hope this was helpful!❤
Answer:
x = -
, x = 
Step-by-step explanation:
Given
x² - x -
= 0
Multiply through by 4 to clear the fraction
4x² - 4x - 3 = 0
Consider the factors of the product of the coefficient of the x² term and the constant term which sum to give the coefficient of the x- term
product = 4 × - 3 = - 12 and sum = - 4
The factors are + 2 and - 6
Use these factors to split the x- term
4x² + 2x - 6x - 3 = 0 ( factor the first/second and third/fourth terms )
2x(2x + 1) - 3(2x + 1) = 0 ← factor out (2x + 1) from each term
(2x + 1)(2x - 3) = 0
Equate each factor to zero and solve for x
2x + 1 = 0 ⇒ 2x = - 1 ⇒ x = - 
2x - 3 = 0 ⇒ 2x = 3 ⇒ x = 