Question

A. y=x^2 + 4x + 4

B. y=-4x^2 + 8x

C. y=-x^2 + 8x

D. y=-x^2 16x + 8

pls help, english pls

Answer 1

Answer:

C. y = -x² + 8x

Step-by-step explanation:

Just put in the values of x and y.

For x = 1, y = -1² + 8×1 = 7

For x = 2, y = - 2² + 8×2 = 12

Answer 2

Answer:

(C). y = - x² + 8x

Step-by-step explanation:

ax² + bx + c = y

~~~~~~~~~~~~~~~

a + b + c = 7

4a + 2b + c = 12

9a + 3b + c = 15

A = $\left[\begin{array}{ccc}1&1&1\\4&2&1\\9&3&1\end{array}\right]$ = - 2

$A_{a}$ = $\left[\begin{array}{ccc}7&1&1\\12&2&1\\15&3&1\end{array}\right]$ = 2

$A_{b}$ = $\left[\begin{array}{ccc}1&7&1\\4&12&1\\9&15&1\end{array}\right]$ = - 16

$A_{c}$ = $\left[\begin{array}{ccc}1&1&7\\4&2&12\\9&3&15\end{array}\right]$ = 0

a = $\frac{A_{a} }{A}$ = - 1

b = $\frac{A_{b} }{A}$ = 8

c = $\frac{A_{c} }{A}$ = 0

y = - x² + 8x