Answer:
40
Step-by-step explanation:
let the unknown be y (x is used as times(multiplication) )
(y-17)x-6=-138
add /-6 to both sides
y-17x-6/-6=-138/-6
y-17=23
make y independent/add 17 to both sides
y-17+17=23+17
y=40
or in an easier way
-138/-6 =23
23+17=40
simply reversing the question to get the answer
Answer:
18 weeks
So we know that she has $1550 dollars, she has a loss of $82.5 dollars every day. It is division (or subtraction to make it easier). She would have her money over $395 dollars for 18 weeks.
Hope this helps!
Well you know that half of 10 is 5 so what is half of 6 = 3 so you can buy 3 books with 5 dollars
-0.9 will be one before -1 and -1.2 will be two after -1
I'm partial to solving with generating functions. Let
Multiply both sides of the recurrence by 
and sum over all 
.
Shift the indices and factor out powers of 
as needed so that each series starts at the same index and power of .
Now we can write each series in terms of the generating function 
. Pull out the first few terms so that each series starts at the same index 
.
Solve for :
Splitting into partial fractions gives
which we can write as geometric series,
which tells us
# # #
Just to illustrate another method you could consider, you can write the second recurrence in matrix form as
By substitution, you can show that
or
Then solving the recurrence is a matter of diagonalizing the coefficient matrix, raising to the power of 
, then multiplying by the column vector containing the initial values. The solution itself would be the entry in the first row of the resulting matrix.
