Answer:
The 2nd one
Step-by-step explanation:
Answer: Multiplying 3x and -x we obtain A= -3x^2
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>
Answer:
hope this helps
Step-by-step explanation:
x = 7
Answer:
Option E.
Step-by-step explanation:
Let the intended length of Rebecca's swimming is = x units
and we assume the length of the pool = l units
Now it is given in the question that " She covers one fifth of her intended distance "
That means distance covered =
" After swimming six more lengths of the pool she had covered one quarter of her intended distance"
So
x = 20×(6l)
x = 120l
Therefore, Rebecca has to complete 120 lengths of the pool.
Option E is the answer.