I = prt
420 = 7000 x .02 x t
420 = 140 x t
420/140 = 140 x t /140
t = 3 years
Answer:
Remember, a homogeneous system always is consistent. Then we can reason with the rank of the matrix.
If the system Ax=0 has only the trivial solution that's mean that the echelon form of A hasn't free variables, therefore each column of the matrix has a pivot.
Since each column has a pivot then we can form the reduced echelon form of the A, and leave each pivot as 1 and the others components of the column will be zero. This means that the reduced echelon form of A is the identity matrix and so on A is row equivalent to identity matrix.
Answer:
10 days
Step-by-step explanation:
It will take 10 men 5 days to dig a hole half as big.
It will take 5 men 10 days to dig a hole half as big.
( Remember, the less people, the more time it will take. )
Common difference r will be the difference between next two values of number row, so we take e.g. second minus first: r=9.4-6=3.4. You can see, that this value is constant as we go through next pairs of values.
