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

geometry: triangles

solvers

lessons

answers archive

call the larger triangle abc

then the smaller triangle cde is similar to abc (all angles are equal, aaa).  

ab is the side that is 36, and we wish to find de, the side corresponding to ab

area_cde = area_abc - area_cde --> area_abc / area_cde = 2

let x=length of de

ratio of areas = (ratio of sides)^2

+2+=+%2836%2fx%29%5e2+

+2+=+1296%2fx%5e2+

++x%5e2+=+1296%2f2+=+648+

25.45584