Answer:
Step-by-step explanation:
(a) The new side length of Ben's garden is (12+x), since x is the amount of increase above the existing 12 ft side length.
The perimeter is the sum of the lengths of the four equal sides, so is ...
perimeter = 4 × side length
104 = 4(12+x)
(b) We can solve this by dividing by 4, then subtracting 12.
26 = 12 +x . . . . . divide the above equation by 4
14 = x . . . . . . . . . subtract 12
The solution is x = 14.