Answer:
I think 5
Step-by-step explanation:
5u^2
just count the no. of squares
if they allocate sides or an area for the small square then:
sides
(side^2 • 5)
eg. the side is equal to 2cm, then
(2^2 • 5) = 4(5)
= 20 cm^2
allocated area for small square
square area • 5
eg. one square has an area of 4 cm^2
4 • 5 = 20 cm^2
(2k+1)(k+3)
14k²+49k+21
simplify by dividing the whole equation by 7
2k²+7k+3
factorise
25x^2-64=0
x=8/5, -8/5
be the length of the square, then the area is 
. Hence, the side is the positive root of the area, which is 