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

There are 6.45 or 6.5 square cm in one square in.
Answer:
17.07m/s
Step-by-step explanation:
v=d/t
d=956km
t=56sec
v=956/56
v=17.07m/s
Answer:
409
Step-by-step explanation:
296 = 200 + 90 + 6
The value of the 9 is 90 in 296.
1/10 of 90 is 9. The only number that has a 9 in the units digit is 409.
Answer:
the fist one is equal to 20