Ok so im not good with words and math, but i am going to try my best to explain it. first you will take 45/60 which is the 45 miles per hour. next you will put it equal to 40/x. x is how many minutes. they are set equal to each other because they are the same ratio. (i honestly dont know why you cross multiply, but you just do). you then multiply 40*60 and 45*x. this gives you 2400=45x. you then divide both sides by 45 and get 53 1/3 minutes. or 53 minutes and 20 seconds
Answer with Step-by-step explanation:
We are given that
A and B are matrix.
A.We know that for two square matrix A and B
Then,
Therefore, it is true.
B. det A is the product of diagonal entries in A.
It is not true for all matrix.It is true for upper triangular matrix.
Hence, it is false.
C.
When is a factor of the characteristics polynomial of A then -5 is an eigenvalue of A not 5.
Hence, it is false.
D.An elementary row operation on A does not change the determinant.
It is true because when an elementary operation applied then the value of matrix A does not change.
Eliminate x's
multiply 2nd equation by -2 ad add to first
2x+3y=9
<u>-2x-10y=-16 +</u>
0x-7y=-7
-7y=-7
divide by -7
y=1
sub back
2x+3y=9
2x+3(1)=9
2x+3=9
minus 3
2x=6
divide 2
x=3
x=3
y=1
(x,y)
(3,1)
D