Step-by-step explanation:
Since AB=I, we have
det(A)det(B)=det(AB)=det(I)=1.
This implies that the determinants det(A) and det(B) are not zero.
Hence A,B are invertible matrices: A−1,B−1 exist.
Now we compute
I=BB−1=BIB−1=B(AB)B−1=BAI=BA.since AB=I
Hence we obtain BA=I.
Since AB=I and BA=I, we conclude that B=A−1.
Answer:
The correct answer is B.
Step-by-step explanation:
In order to find this, calculate out the discriminant for each of the following equations. If the discriminant is a perfect square, then it can be factored.
Discriminant = b^2 - 4ac
The only of the equations that does not yield a perfect square is B. The work for it is done below for you.
Discriminant = b^2 - 4ac
Discriminant = 7^2 - 4(2)(-5)
Discriminant = 49 + 40
Discriminant = 89
Since 89 is not a perfect square, we cannot factor this.
Answer:
L=29ft
W=15ft
Step-by-step explanation:
Step one:
given
let the width be x
W=x
L= x+14
P= 88ft
perimeter= 2L+2W
so, substituting our data we have
88=2(x+14)+2x
88=2x+28+2x
collect like terms
88=4x+28
88-28=4x
60=4x
divide both sides by 4
x=60/4
x=15
Step two:
the dimensions are
the width is 15ft
the length= 15+14
L=29ft
