Answer:75
Step-by-step explanation:2 1/2 is equal to 5 halves. If each half is equal to 15 then all you do is multiply 15 by 5
The standard form for this parabola is x = a(y-k)^2 + h because this is a sideways-opening parabola. Our h and k values for the vertex are (-4, -1). And it goes through (2,0). We just need to solve for the a. Filling in accordingly, 2 = a(0+1)^2-4 so 2 = a - 4. a = 6. A above.
correct answer is 6!
Answer:
y = (x - 4)² - 25
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
To obtain this form use the method of completing the square.
Given
y = (x + 1)(x - 9) ← expand factors using FOIL, thus
y = x² - 8x - 9
To complete the square
add/subtract ( half the coefficient of the x- term )² to x² - 8x
y = x² + 2(- 4)x + 16 - 16 - 9
= (x - 4)² - 25 ← in vertex form
3x : 2 = 15
3x = 15 * 2
3x = 30
x = 30 : 3
x = 10
--------------------------------
3(10) :2 = 15
