Answer:
4
Step-by-step explanation:
The original number is 7 i think.
10(x^2) = 70x
10x^2 - 70x = 0
x^2 -7x =0
Δ= b^2 -4ac
where c doesnt exist=0
Δ= 49
-b ± √Δ /2a
7 ± √49 /2
7±7/2
x is either 14/2= 7
or 1/2, which doesnt work.
Lets see:
10(7^2) = 70•7
10•49 = 490
and that is right.
i hope my logic is correct.
Answer:

which is the first option in the list of possible answers.
Step-by-step explanation:
Recall that the minimum of a parabola generated by a quadratic expression is at the vertex of the parabola, and the formula for the vertex of a quadratic of the general form:

is at 
For our case, where
we have:

And when x = 1, the value of "y" is:

Recall now that we can write the quadratic in what is called: "vertex form" using the coordinates
of the vertex as follows:

Then, for our case:

Then, for the quadratic equal to zero as requested in the problem, we have:
