+120 Iskander, Anthony and Sean have a total of 555 stamps. Anthony has 13 more stamps than Iskander. Sean has twice the total number of stamps as Anthony and Iskander have. How many stamps does Anthony have?
+63 Let's write it out using algebra. Iskander is I, Anthony is A, and Sean is S.
I+A+S=555
A= I+13
S=(A+I)2
Let's solve for I first.
Lets bring A= I+13 into S=(A+I)2
S=((I+13)+I)2
S=(2l+13)2
S=4I+26
Lets bring S=4I+26 and A= I+13 into I+A+S=555
I+I+13+4l+26=555
6I=516
I=86
But, we want A. So we bring I=86 into A= I+13.
A=86+13
A=99
Hope this helps.
