Answer :
Sari has 21 and Sam has 7
7x4=28 which is the total, so you just need to split it up so that you get 7 and 21 which is 3 times more than 7.
Let
x--------> the number of Saris pencil erasers
y--------> the number of Sams pencil erasers
we know that
[tex] x+y=28\\ x=28-y [/tex]
equation [tex] 1 [/tex]
[tex] x=3y [/tex]
equation [tex] 2 [/tex]
equate equation 1 and equation 2
so
[tex] 28-y=3y\\ 4y=28\\ y=7 [/tex]
[tex] x=3*7\\ x=21 [/tex]
therefore
the answer is
the number of Saris pencil erasers is [tex] 21 [/tex]
