Answer:
D
Step-by-step explanation:
x² - 81 ← is a difference of squares and factors in general as
a² - b² = (a + b)(a - b)
Here a = x and b = 9, thus
x² - 81 = (x + 9)(x - 9) → D
Answer: 0
Step-by-step explanation:
The disciminant \Delta tells you how many real solutions a quadratic equation has, depending on its sign:
\Delta>0\implies\text{2 solutions}\\\Delta=0\implies\text{1 solution}\\\Delta<0\implies\text{no solutions}
One way to solve this question is through trigonometry. :)
If you've learnt trigonometry, here are the basic formulas:
SOH CAH TOA (These formulas only apply for right-angled triangles)
Sin(angle) = (Side that is Opposite of angle)/(Hypotenuse)
Cos(angle) = (Side that is Adjacent of angle)/(Hypotenuse)
Tan(angle) = (Side that is Opposite of angle)/(Side that is Adjacent of angle)
In this case, we should use sine of b (the angle at the top of triangle as indicated in your question), where the opposite side is the base (I.e. 4 indicated in your question) and the hypotenuse is 9.
sin(b) = 4/9
{Make angle b the subject of the equation}

{Type this into the calculator}
Angle b = 26.4° (rounded off to 1 decimal place)
Hope this helps! :)
Answer: The number of batches made by Vanessa last weekend = 5
Number of batches made this weekend =20
Step-by-step explanation:
Let x be the number of batches made y Vanessa last weekend.
Given : This weekend Vanessa made 4 times as many batches as last weekend.
i.e. Number of batches made this weekend = 4x
She made a total of 25 batches for the two weekends.
i.e. 

Divide both sides by 5 , we get

i.e. number of batches made y Vanessa last weekend = 5
Number of batches made this weekend =20
Hence, the number of batches made by Vanessa last weekend = 5
Number of batches made this weekend =20
<em>Hello there, and thank you for asking your question here on brainly.
<u>Short answer: 3
</u>
Why?
You can find this out by dividing 48 and 16. The number you get from it is how much 16s are in 48, which is the answer to our question. (48 / 16 ==> 3) Check: 16 * 3 = 48. This is correct.
Hope this helped you! ♥</em>