Answer:
20 years old
Step-by-step explanation:
Joe = J
Sydney = S
J = 5 + S
J + S = 45
Substitute
5 + S + S = 45
Add
5 + 2S = 45
Subtract 5 from both sides of the equation
2S = 40
Divide both sides of the equation by 2
S = 20
Sydney is 20 years old
Hope this helps :)
You can’t solve this, not enough information
Answer:
Kay sold 67; Allen sold 50
Step-by-step explanation:
Let "a" represent the number of phones that Allen sold.
a + (a+17) = 117 . . . equation used to find the answer
2a = 100 . . . . . . . . subtract 17, collect terms
a = 50 . . . . . . . . . . divide by 2; the number Allen sold
a+17 = 67 . . . . . . . . Kay sold 17 more than Allen
Perimeter of a rectangle: 2(l+w)
Let width be 'x'
Length is 3 meters more than twice 'x'
Length= 2x+3.
L= x
W = 2x+3
Formula =
2(x+2x+3)
2(3x+3)
6x+6.
6(x+1)
The system of equations when been placed in a matrix yields
![\left[\begin{array}{ccc}650&-1\\120&1\end{array}\right]\left[\begin{array}{ccc}x\\y\end{array}\right] =\left[\begin{array}{ccc}-175\\25080\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D650%26-1%5C%5C120%261%5Cend%7Barray%7D%5Cright%5D%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7Dx%5C%5Cy%5Cend%7Barray%7D%5Cright%5D%20%20%3D%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D-175%5C%5C25080%5Cend%7Barray%7D%5Cright%5D)
<h3>What is an
equation?</h3>
An equation is an expression that shows the relationship between two or more variables and numbers.
Given the equation:
y = 650x + 175 and;
y = 25080 - 120x
Rearranging the equations gives:
650x - y = -175 and;
120x + y = 25080
Placing the equations in a matrix gives:
![\left[\begin{array}{ccc}650&-1\\120&1\end{array}\right]\left[\begin{array}{ccc}x\\y\end{array}\right] =\left[\begin{array}{ccc}-175\\25080\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D650%26-1%5C%5C120%261%5Cend%7Barray%7D%5Cright%5D%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7Dx%5C%5Cy%5Cend%7Barray%7D%5Cright%5D%20%20%3D%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D-175%5C%5C25080%5Cend%7Barray%7D%5Cright%5D)
The system of equations when been placed in a matrix yields
![\left[\begin{array}{ccc}650&-1\\120&1\end{array}\right]\left[\begin{array}{ccc}x\\y\end{array}\right] =\left[\begin{array}{ccc}-175\\25080\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D650%26-1%5C%5C120%261%5Cend%7Barray%7D%5Cright%5D%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7Dx%5C%5Cy%5Cend%7Barray%7D%5Cright%5D%20%20%3D%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D-175%5C%5C25080%5Cend%7Barray%7D%5Cright%5D)
Find out more on equation at: brainly.com/question/2972832
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