Answer:
x = 2 + sqrt(5) or x = 2 - sqrt(5)
Step-by-step explanation using the quadratic formula:
Solve for x over the real numbers:
7 (x^2 - 4 x - 1) = 0
Divide both sides by 7:
x^2 - 4 x - 1 = 0
Add 1 to both sides:
x^2 - 4 x = 1
Add 4 to both sides:
x^2 - 4 x + 4 = 5
Write the left hand side as a square:
(x - 2)^2 = 5
Take the square root of both sides:
x - 2 = sqrt(5) or x - 2 = -sqrt(5)
Add 2 to both sides:
x = 2 + sqrt(5) or x - 2 = -sqrt(5)
Add 2 to both sides:
Answer: x = 2 + sqrt(5) or x = 2 - sqrt(5)
let's first off take a look at the <u>tickmarks</u>, three <u>side tickmarks</u>, so all those 3 sides are equal, all have a length of y - 25, so is an equilateral triangle.
there are two <u>angle tickmarks</u>, meaning those two angles are equal, wait a second! if those two angles are equal, that means is an isosceles triangle.
now, in an equilateral triangle, all sides are equal, but also all angles are equal, since the sum of all interior angles is 180°, then each angle is really 60°.
let's notice that angle on the upper-left-corner, is a right-angle, but 60° are on the equilateral triangle, and so the remaining 30° must be on the isosceles triangle.
the isosceles triangle has then a vertex of 30°, and twin angles, the twin angles let's say are each a° so then
30° + a° + a° = 180°
30 + 2a = 180
2a = 150
a = 75° = y
now, let's recall, the isosceles triangle has twin angles but it also has twin sides, so the side "x" and the side with the tickmark are equal.
well, we know that y = 75, so the sides with the tickmark are then (75) - 25 = 50 = x.
Answer:
Area of the walkway border is 736 ft²
Step-by-step explanation:
A rectangle is a quadrilateral (has four sides and four angles) with two pairs of opposite and parallel sides. All angles in a rectangle are 90 degrees each. Also, opposite sides are equal.
The entire pool area has a length of 60 feet and width of 40 feet. The area of the entire pool area is:
Area of entire pool = length * width = 60 feet * 40 feet = 2400 ft²
The area of entire pool
A walkaway border of 4 ft is made around the pool area. There is a decrease of 4 ft round the sides of the pool area.
Therefore length of pool = length of entire pool area - 4 feet border at left - 4 feet border at right = 60 ft - 4 ft - 4 ft = 52 ft
width of pool = width of entire pool area - 4 feet border at top - 4 feet border at bottom = 40 ft - 4 ft - 4 ft = 32 ft
Therefore the pool is 52 ft × 32 ft
Area of pool = length * width = 52 ft * 32 ft = 1664 ft²
Area of the walkway border = Entire pool area - Area of pool = 2400 ft² - 1664 ft² = 736 ft²
