Given

we have

Squaring both sides, we have

And finally

Note that, when we square both sides, we have to assume that

because we're assuming that this fraction equals a square root, which is positive.
So, if that fraction is positive you'll actually have roots: choose

and you'll have

Which is a valid solution. If, instead, the fraction is negative, you'll have extraneous roots: choose

and you'll have

Squaring both sides (and here's the mistake!!) you'd have

which is not a solution for the equation, if we plug it in we have

Which is clearly false

Two lines are parallel when their slopes are the same.
Answer:
19°
Step-by-step explanation:
I have attached an image showing this elevation.
From the image, let's first find the angle A by using cosine rule.
Thus;
8.1² = 5.5² + 13.1² - 2(5.5 × 13.1)cos A
65.61 = 30.25 + 171.61 - 144.1cos A
144.1cos A = 171.61 + 30.25 - 65.61
144.1cosA = 136.25
cosA = 136.25/144.1
cosA = 0.9455
A = cos^(-1) 0.9455
A = 19°
X is not anything unless you show the equation with the variable
Answer:

Step-by-step explanation:
we know that
An isosceles triangle has two equal sides and two equal angles
so
The perimeter of triangle is equal to

Eliminate parenthesis

Combine like terms
