Answer:
l = 
Step-by-step explanation:
Given
P = 2(l + w) ← distribute right side
P = 2l + 2w ( subtract 2w from both sides )
P - 2w = 2l ( isolate l by dividing both sides by 2 )
= l
Grouping similar factors together makes this easier:
(8)(2)(10^7)(10^6) = 16(10^13) = 1.6(10^14)
Vertical is left to right or right to left
Horizontal is up to down or down to up