He started with 17 quarter's. He had a certain number of quarters he added to his collection each day, on day two he had 26, and two days later he had 35, meaning he increased the amount of quarters my 9 over two day's, so I subtracted 9 from 26 because if you do you can remove the quarters he added in from the ones he started with, so the answer is: He started with 17.
Answer:
1
Step-by-step explanation:
5/7+2/7 add the numerator to equal 7/7 simplify to 1/1 equals 1
A(c - b) = d
ac - ab = d
ac = d + ab
c = (d + ab)/a
Answer:

where
is the number of laptops, and
is the year.
in 2017: 
Step-by-step explanation:
I will define the variable
as the number of years that passed since 2007.
Since the school buys 20 lapts each year, after a number
of years, the school will have
more laptops.
and thus, since the school starts with 31 laptops, the equation to model this situation is

where
is the number of laptops.
since x is the number of years that have passed since 2007, it can be represented like this:

where
can be any year, so the equation to model the situation using the year:

and this way we can find the number of laptos at the end of 2017:

and


Looking at the angles of the triangles
N=S
M=R
O=T
so MON would be RTS