Let
x ----> total hot dogs sold by My Dawg
y ----> total hot dogs sold by Hot Dog Heaven
z ----> total hot dogs sold by Hot Cats
so
x+y+z=3,195 ------> equation 1
x=3y-100 ----> equation 2
z=2y+25 ----> equation 3
Solve the system of equations
Substitute equation 2 and equation 3 in equation 1
(3y-100)+y+(2y+25)=3,195
solve fr y
6y-75=3,195
6y=3,195+75
6y=3,270
y=545
Find out the value of x
x=3y-100 -----> x=3(545)-100=1,535
Find out the value of z
z=2y+25 -----> z=2(545)+25=1,115
therefore
The answer is
My Dawg 1,535
Hot Dog Heaven 545
Hot Cats 1,115