Triangles have 3 vertices. The total is 21 vertices. 21 / 3 = 7. He drew 7 triangles.
Answer:
x = -1.14 or -13.14
Explanations:
The given equation is:

Find the half of 12, and add the square to both sides of the equation.
That is add 6² to both sides


Find the square root of both sides:
![\begin{gathered} \sqrt[]{(x+6)^2_{}}=\pm\sqrt[]{51} \\ \text{x + 6 = }\pm\sqrt[]{51} \\ x\text{ = -6 }\pm\sqrt[]{51} \\ \text{x = }-6\pm7.14 \\ x\text{ = -6+7.14 = }1.14 \\ x\text{ = -6 - 7.14} \\ \text{x = -13.14} \end{gathered}](https://tex.z-dn.net/?f=%5Cbegin%7Bgathered%7D%20%5Csqrt%5B%5D%7B%28x%2B6%29%5E2_%7B%7D%7D%3D%5Cpm%5Csqrt%5B%5D%7B51%7D%20%5C%5C%20%5Ctext%7Bx%20%20%2B%20%206%20%20%3D%20%7D%5Cpm%5Csqrt%5B%5D%7B51%7D%20%5C%5C%20x%5Ctext%7B%20%20%3D%20%20-6%20%20%7D%5Cpm%5Csqrt%5B%5D%7B51%7D%20%5C%5C%20%5Ctext%7Bx%20%20%3D%20%7D-6%5Cpm7.14%20%5C%5C%20x%5Ctext%7B%20%20%3D%20-6%2B7.14%20%20%3D%20%7D1.14%20%5C%5C%20x%5Ctext%7B%20%3D%20-6%20-%207.14%7D%20%5C%5C%20%5Ctext%7Bx%20%3D%20-13.14%7D%20%5Cend%7Bgathered%7D)
x = -1.14 or -13.14
Answer:
x ≈ 25.4 Km
Step-by-step explanation:
Using the tangent ratio in the right triangle on the right
tan54° =
=
( multiply both sides by 17 )
17 × tan54° = opp , thus
opp ≈ 23.4
-------------------------------------------
Using the cosine ratio in the right triangle on the left
cos23° =
=
( multiply both sides by x )
x × cos23° = 23.4 ( divide both sides by cos23° )
x =
≈ 25. 4 Km ( to the nearest tenth )
x-intercept = (15, 0) y-intercept = (0, 3)
slope (m) = (y₂ - y₁)/(x₂ - x₁) = (0 - 3)/(15 - 0) = -3/15 = -1/5
Point-Slope formula: y - y₁ = m(x - x₁) ; where (x₁, y₁) is one of the given points
y - 0 = (-1/5)(x - 15)
-5y = x - 15
x + 5y = 15
Answer: x + 5y = 15