Arectangle has an area of 105 ft.² if the sum of the length and width is 26 feet find the dimensions include units

LW=105
L+W=26
L=26-W
(26-W)W=105
26W-W^2=105
0=W^2-26W+105
-105=W^2-26W
-105+169=W^2-26W+169
64= (W-13)^2
8= -(W-13) and (W-13)
8= -W+13
5=W

8= W-13
21=W

105= 5*21

5 feet x 21 feet