one side of the equation has to equation the other so imagine the equal sign is a balance scale.
first lets figure out the left hand side.
15/5 = 3 simple right?
now lets figure out the right hand side
since we know that they have to equal each other lets divide 20 by 3
20/3 = 6.666666667
so n equals 6.666666667
or rounded up 6.7:)
