B: (0, a)
C should have the same y value as B
D: (a,0)
C should have the same x value as D
So point C is (a,a)
Since point A is on the origin, its point is (0,0)
You use the slope formula and plug in point A and C:



m = 1
So the value that belongs in the green box is 1
<span>We write the equation in the standard form which is:
ax^2 + bx + c = 0
(x + 15)(x) = 100
x^2 + 15x - 100 = 0
(x + 20) (x-5) = 0
The solutions are
x = -20 and x = 5
Therefore, the correct answer is option B. </span><span>The solution x = 5 should be kept, but x = –20 is unreasonable.</span><span>
</span>
What do you need me to answer