Answer:
x = 13
Step-by-step explanation:
Note that the side length x is opposite of the right angle, which means that it is the hypotenuse, which will usually be denoted as c.
Set the equation:
a² + b² = c²
let:
a = 5
b = 12
c = x
Plug in the corresponding numbers (& x) to the corresponding variables:
(5)² + (12)² = (x)²
Simplify. First, solve for the power, and then add:
x² = (5²) + (12²)
x² = (5 * 5) + (12 * 12)
x² = 25 + 144
x² = 169
Next, root both sides of the equation:
√x² = √169
x = √169 = √(13 * 13) = 13
x = 13
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Note the rules, and it should be easier:
30-60-90° = 1 , √3 , 2
45-45-90° = 1 , 1 , √2
Any other measurements use the equation: a² + b² = c²
Step-by-step explanation:
This is the correct answer.
Even according to calculator and working.
So not quite sure why those options are incorrect?
We are to verify the identity:
cos(α-B)-cos(α+B) = 2 sinα sinβ
Left hand side = cos(α - B)-cos(α + B)
= cosα cosβ + sinα sinB - (cosα cosB - sinα sinβ)
= cosα cosβ + sinα sinB - cosα cosB + sinα sinβ)
= sinα sinβ + sinα sinβ
= 2 sinα sinβ
= Right Hand side
<span>Simplifying
-15x2 + -2x + 8 = 0
Reorder the terms:
8 + -2x + -15x2 = 0
Solving
8 + -2x + -15x2 = 0
Solving for variable 'x'.
Factor a trinomial.
(2 + -3x)(4 + 5x) = 0
Subproblem 1Set the factor '(2 + -3x)' equal to zero and attempt to solve:
Simplifying
2 + -3x = 0
Solving
2 + -3x = 0
Move all terms containing x to the left, all other terms to the right.
Add '-2' to each side of the equation.
2 + -2 + -3x = 0 + -2
Combine like terms: 2 + -2 = 0
0 + -3x = 0 + -2
-3x = 0 + -2
Combine like terms: 0 + -2 = -2
-3x = -2
Divide each side by '-3'.
x = 0.6666666667
Simplifying
x = 0.6666666667
Subproblem 2
Set the factor '(4 + 5x)' equal to zero and attempt to solve:
Simplifying
4 + 5x = 0
Solving
4 + 5x = 0
Move all terms containing x to the left, all other terms to the right.
Add '-4' to each side of the equation.
4 + -4 + 5x = 0 + -4
Combine like terms: 4 + -4 = 0
0 + 5x = 0 + -4
5x = 0 + -4
Combine like terms: 0 + -4 = -4
5x = -4
Divide each side by '5'.
x = -0.8
Simplifying
x = -0.8
Solutionx = {0.6666666667, -0.8}</span>
