1.
Let N be the number of coins of Alex
2a+1=N
3b+1=N
4c+1=N
5d+1=N
6e+1=N
7f+1=N
so N-1 is a multiple of 2, of 3, of 4, of 5, of 6 and of 7
so N-1 has factors 7*6*5*2*X, where X is another factor.
2.
There is no need to write N-1 as 7*6*5*3*2*4, since being a multiple of 6, means being a multiple of 2, and of 3 as well. Also, no need to write *4, since 6 has already *2, but we need one more 2, that why we write 7*6*5*2*X
(7*6*5*2=420 is the LCM, least common multiple of 2,3,4,5,6,7)
3.
N-1=420*X.
X cannot be 2 or more since N would become larger that 800.
X must be 1, so N-1=420, which means N=421 is the number of coins
Answer:
1.25992105
Step-by-step explanation:
To 1 d.p
1.3
Answer:
A. pen, $0.75; pencil, $0.50.
step-by-step explanation: .75x4=$3.00. .50x4=$2.00 . $3.00+$2.00=$5.00
The point 0,-7 C , is not a solution
14.57 is what your looking for.