We need more to answer the question I think
Answer:
Step-by-step explanation:
The equation Thomas wrote is:
...equation 1
Let us subtract 3x from both sides to get:
We now multiply through by 2 to get:
....equation 2
We can see that equation one and two are equivalent and hence have the same solution.
Therefore Sandra's equation is 
Answer:
The solution of the given equations
x =4 , y = 1
Step-by-step explanation:
<u>Explanation</u>:-
<u>Step(l</u>):-
Given the system of equations -5x+13y = -7 ..(l)
5x+4y=24 ..(ll)
<u>Step(ll)</u>
Adding (l) and (ll) equations and cancelling '5x' terms we get
13y+4y = -7 +24
17y = 17
dividing '17' on both sides, we get
y=1
<u>Step(lll):-</u>
Substitute y=1 in equation (l) , we get
-5x+13y = -7
-5x + 13(1) = -7
subtracting '13' on both sides, we get
-5x +13 -13= -7 -13
-5x = -20
Dividing '-5' on both sides, we get

x = 4
<u>Conclusion</u>:-
The solution of the given equations
x =4 , y = 1
Multiply 8 total hours by 1/4 to find the number of piano hours.
= 8 * 1/4
= (8*1)/4
= 8/4
= 2 piano hours
ANSWER: He practiced piano for 2 hours.
Hope this helps! :)