What is the product of (-a + 3) (a + 4) ?

Step-by-step explanation:

multiply the first bracket with the second

and get - a squared - 4a+3a+12

then we group like and unlike terms

so - 4a+3a = - a

our new equation will be - a (squared) - a+12=0

we equals to zero to remove negative signs and it will be

a squared + a-12

then we find the factors.

And our factors are 3a-4a

=a squared + 3a-4a-12=0

We factorise and answer will be

(a+3) (a-4) = 0

so a = - 3 or 4