Answer:
-10.4
Step-by-step explanation:
If k=8
then, -1.3k=-1.3x8 = -10.4
So hmm notice the picture below
running a segment from the right-angle perpendicular to the opposite side, gives three similar triangles, one small, a medium and a large one
now, using proportions, you can simply

and solve for "x"
Answer:
x = 4, x = 3/2
Step-by-step explanation:
3(x - 4)(2x - 3) = 0
x - 4 = 0 , or 2x-3 = 0
x = 4, x = 3/2
Answer:
The trestle meets ground level at 0.9 units and 9.1 units
Step-by-step explanation:
∵ -x² + 10x - 8 = 0 ⇒ × (-1)
∴ x² - 10x + 8 = 0
∵ 10x/2 = 5x ⇒ (x) × (5) ⇒ square x is x² and square 5 is 25
By using completing square form
∴ (x² - 10x + 25) - 25 + 8 = 0
∴ (x - 5)² - 17 = 0
∴ (x - 5)² = 17 ⇒ take square root for both sides
∴ x - 5 = -√17 ⇒ x = -√17 + 5 = 0.9
∴ x - 5 = √17 ⇒ x = √17 + 5 = 9.1
∴ The trestle meets ground level at x = 0.9 and x = 9.1