Answer:
a+b = b+a
Step-by-step explanation:
Answer:
The answer is 3.19, someone irrationally deleted my answer previously.
Step-by-step explanation:
Simply substract 2.95 from 18.90 and you will get 15.95
Divide this by 5 to get the price of each and you will get $3.19 which is the correct answer.
I'm not great at math but I believe the answer is $6.30
X + k y = 1
k x + y = 1 / * ( - k )
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x + k y = 1
- k² x - k y = - k
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x - k² x = 1 - k
x ( 1 - k² ) = 1 - k
x = ( 1 - k ) / ( 1 - k² ) = ( 1 - k ) / ( 1 - k ) ( 1 + k )
y = 1 - k( 1 - k )/( 1 - k² )
y = ( 1 - k ) / ( 1 - k² ) = ( 1 - k ) / ( 1 - k ) ( 1 + k )
a ) For k = - 1 this system has no solution.
b ) For k ≠ - 1 and k ≠ 1, the system has unique solution:
( x , y ) = ( 1/ (1 + k) , 1/( 1 + k ) ).
c ) For k = 1, there are infinitely many solutions.
The expression (−81)(−9) will give the value of 729.
<u>Step-by-step explanation:</u>
The given expression is (−81)(−9)
.
The both numbers in the expression are negative numbers and they are given inside the brackets.
This means that, the negative numbers must be multiplied to get a final value.
<u>The rules in multiplication are :</u>
- Positive number × Positive number = positive number
- Negative number × Positive number = negative number
- Positive number × Negative number = negative number
- Negative number × Negative number = positive number
From the rules, it can be determined that the result of any two negative numbers will be a positive number.
So, eliminate option A) and B) because they have negative sign.
The expression (−81)(−9) = -81 × -9
⇒ 729.
Therefore, the option C) and D) are not in match with 729. None of the options are not the value of the given expression (−81)(−9).
