Data Sufficiency

now sure how to approach this type of problem

Hi,

Thanks ... Interesting question ...

1. -a and -b are the points where the curve meets the x-axis. However, we do not know their numeric values

a + b = -1

Implies a = 5 and b = -6

or

a = 10 and b = -11 (besides the millions of other possibilities). Hence, Insuff.

2.

y = (x + a) (x + b)

If (0,-6) lies on this graph, then

-6 = (0+a) * (0+b)

ab = -6

This implies a = -3 and b = 2

or

a = -6 and b = 1 (besides other possibilities). Hence, insuff

3. Combine both

a + b = -1

ab = -6

Here, a = -3 and b = 2

or

a = 2 and b = -3

However, the curve becomes y = (x + 2) (x - 3). The curve passes through (-2,0) and (3,0). Hence, suff.

My take is C. Please correct / confirm.

Thanks !

thanks OA: C