A partir del 1.° de diciembre, un camión de helados visita la calle de Sara cada 3 días y la calle de Ema cada 5 días. ¿Cuáles s
1 answer:
You might be interested in
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