2x+y=9
3x+5y=19
I will do this problem in 2 ways. I.)Substitution II.)Elimination
Solution I.) Substitution
We can subtract 2x from both sides in the first equation.
y=9-2x
Now we can substitute the y in the second equation with 9-2x
3x+5(9-2x)=19
-7x+45=19
-7x=-26
x=26/7
y=9-2(26/7)=11/7
Solution II.)Elimination
We can multiply both side of first equation by 5 to get a 5y in both equations.
10x+5y=45
Now because both are positive 5y we just need to do simple subtraction of the 2 equation, each side respectively.
(10x+5y)-(3x+5y)=45-19
7x=26
x=26/7
2*26/7+y=9
y=11/7
Ultimately you get the same answer, both are viable methods, some problems are faster with one method but I recommend mastering both since they are very useful.
Answer:
7
Step-by-step explanation:
did the math
No. We claim that
and use algebra to prove the statement.
Let
. Multiply this by ten to get
. Subtract the initial equation to give
and divide by
to see that
. Substituting into the original equation gives
, proving the desired statement.
Answer: The required expected value is $3.46.
Step-by-step explanation:
Since we have given that
Number of value of 4 or less are
2,3,4
So, there are 12 in numbers.
So, probability would be
Since Aces are considered as the highest card in the deck.
So, remaining probability would be
Amount paid or value of 4 or less = $165
Amount not paid for other case = $45
So, the expected value would be
Hence, the required expected value is $3.46.
Answer: a) , where 'A' is the value of car after 't' years.
b) $12446.784
Step-by-step explanation:
Given: A new car that sells for $21,000 depreciates (decreases in value) 16% each year.
Then a function that models the value of the car will be
, where 'P' is the selling price of car, 'r' is the rate of depreciation in decimal, 't' is the time in years and 'A' is the value of car after 't' years.
Thus after substituting given value, the function becomes
To find the value after 3 years, substitute t=3 in the above function.
Hence the value of car after 3 years=$12446.784
