The greatest common multiple is 9, so each row will have 9 trees of one kind.
A = L * W
Given: The area of a rectangle is 70 m^2
L * W = 70
L = 3W - 11
Substitute L = 3W - 11 into L * W = 70
(3W - 11) * W = 70
3W^2 - 11W = 70
3W - 11W - 70 = 0
(3W + 10) (W - 7)= 0
3W + 10 = 0; W = -10/3 (Dimension can't be negative)
W - 7 = 0; W = 7
L = 3W - 11 = 3(7) - 11 = 21 - 11 = 10
Answer
Length: 10 m
Width: 7 m
I am not really sure about this one because I can only read a little bit of Spanish but it should be C.(4 Decenii).<span />