How to solve it and the formula to solve it
1 answer:
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Answer:
x =
Step-by-step explanation:
Given
3x + k = c ( isolate the term 3x by subtracting k from both sides )
3x = c - k ( divide both sides by 3 )
x =
Let p be the prize of a pen and m the prize of a mechanical pencils. If you buy six pens and one mechanical pencil, you spend 6p+m. We know that this equals 9, because you get 1$ change from a 10$ bill.
Similarly, if you buy four pens and two mechanical pencils, you spend 4p+2m, which is 8$, because now you get a $2 change. Put these equation together in a system:
Now, if you multiply the first equation by 2, the system becomes
Subtract the second equation from the first:
Plug this value into the first equation to get