Vertex form of a parabola
<span>y = a (x - h)^2 + k </span>
<span>where (h, k) is the vertex </span>
Substituting the values of h and k.
we get,
<span>y = a(x + 4)^2 + 2 </span>
<span>substituting in the point (0, -30) for x and y
</span><span>-30 = a (0 + 4)^2 + 2
</span>solve for a,
<span>-30 = 16 a + 2 </span>
<span>-32 = 16 a </span>
<span>-2 = a </span>
<span>y = -2(x + 4)^2 + 2 </span>
<span>Put y = 0 </span>
<span>-2 x^2 - 16 x - 30 = 0 </span>
<span>-2(x^2 + 8 x + 15) = 0 </span>
<span>x^2 + 8 x + 15 = 0 </span>
<span>(x + 3)(x + 5) = 0 </span>
<span>x = -3
x = -5</span>
8-(8+48) = -48 then divide that by 8 and you get -6 as your result
Answer:
(-3,-20)
Step-by-step explanation:
4 +8x = y ...... equation (1)
6x - y = 2 ........equation(2)
from equation 2
6x - y = 2
6x -(4+8x) =2
6x - 4 + 8x = 2
+4 +4
6x - 8x = 6
-2x=6
divide by -2
x= -3
put x in equation (1) to solve for y
4 + 8x = y
4+8(-3)=y
4-24=y
-20=y
y= -20
solution = (-3,-20)
The table on the far left
You can tell because every time the x value increases by 1, the y value increases by exactly 1/2 every time
