Find the product: 2 7 1 3 1 -2
-21-63
13
cd
X => 0 c =
11
|X = 1b =
X = 0
X = 1
d =
COMPLETE
The product above is equal to the identity
matrix.
COMPLETE

answer: a.   one is a factor of every whole number since every number is divisible by itself.

tangent

step-by-step explanation:

we have three similar triangles, because each has a right angle and shares an angle.   let's write the angles in order: opposite to short leg, long leg, hypotenuse.

cab similar to bad similar to cbd

or as ratios,

ca: ab: cb = ba: ad: bd = cb: bd: cd

we also know

ac = ad + cd

(ad+cd): ab: cb = ba: ad: bd = cb: bd: cd

(ad+cd)/cb=cb/cd

we have cb=6, ad=5 and seek x=cd.

we reject the negative root and conclude x=4

answer: 4