Quick I need help plz

It's answer is 1/3 .

Hope it helps have a great time :)

Step-by-step explanation:

The easiest way to get the answer is to convert the decimal form into its fraction form. All you have to do is to take note of the number of decimal places in order to raise the number into the power of ten. 0.3 has one decimal place, thus, you can use 10.

Since there's no common factor, there's no cancellation needed. So, the answer is .

Let' check.

If you divide 3 by 10, you will get the answer 0.3.

You can get equivalent fractions to this by multiplying or dividing the numerator by the same number.

Example: x =

You may also use the fraction for your answer as this is also equivalent to 0.3.

Correct  cos(α - β) = 140/221

Step-by-step explanation:

cosα = ±√(1 - sin²α) => cosα = ±√(1 - (-5/13)²) = ±√(1 - (25/169)  

cosα = ±√(169 -25)/169 = ± √144/169

cosα = ± 12/13  since it is given that α (alpha) ends in the third quadrant

we choose  cosα = - 12/13

we know that is  tanβ = sinβ/cosβ = - 8/15 or sinβ : cosβ = 8 : 15 =>

sinβ = 8k and cosβ = 15k  where k is the coefficient of proportionality

we know the basic trigonometric equality

sin²β + cos²β = 1    when we replace the coefficients we get

(8k)² + (15k)² = 1 => 64k² + 225k² = 1 => 289k² = 1 => k² = 1/289 =>

k = 1/17   now we get sinβ and cosβ

since it is given that  β (beta) ends in the second quadrant

sinβ = 8/17 and cosβ = - 15/17

As we know it is:

cos(α - β) = cosα cosβ + sinα sinβ = - 12/13 · (- 15/17) + (- 5/13) · 8/17 =>

cos(α - β) = 180/221 - 40/221 = 140/221

cos(α - β) = 140/221

God is with you!!!