24=2(w+4)+2w=4w+8, subtract 8 from both sides 4w=16, w=4. L=w+4 so l is 8. The dimensions are 8 by 4.
You multiply 86 by 42.5 because each board is 42.5 and there are 86 boards.
D = sq.root of((x2 - x1)^2 + (y2 - y1)^2)
sq.root of 13 = sq.root of((x - (-2))^2 + (1 - 3)^2)
= sq.root of((x + 2)^2 + (-2)^2)
= sq.root of (x^2 + 4x + 4 + 4)
= sq.root of (x^2 + 4x + 8)
Now if we square both sides:
x^2 + 4x + 8 = 13
x^2 + 4x - 5 = 0
(x + 5)(x - 1) = 0
x = -5 or x = 1
(10x + 4) + (5x-4) ≈ 180
solve for x and you get x≈12
plug 12 in to 5x-4 and you get 56