When factoring a trinomial of the form ax2 + bx + c where a, b, and c are all positive, you need to find two numbers, m and n, such that ax2 + bx + c = ax2 + mx + nx + c and

A. m and n both are positive is correct choice.

Step-by-step explanation:

We have been given that When factoring a trinomial of the form ax2 + bx + c where a, b, and c are all positive. That means:

a>0

b>0

c>0

Then ac>0 as product of same sign numbers is always positive.

Positive produce ac is  possible only when both factors are of same sign.

In this situation, b>0 is possible only if both numbers are positive.

Hence choice A. m and n both are positive is correct choice.