You can do this by comparing your equation to the general form of equation of a circle
( x - a)^2 + (y - b)^2 = r^2 where (a,b) is the centre and r = radius:-
(x + 9)^2 (y + 6)^2 = 9
so (a,b) = (-9,-6) and r = 3
so the answer is B
In a triangle all of the angles always add up to 180, so let's set up an equation.
79 + 37 + y = 180
Simplify
116 + y = 180
Subtract 116 from both sides.
y = 64
The value of y is 64.
Hopefully this helps! If you have any more questions or don't understand, please comment or DM me, and I'll get back to you ASAP. :)
Answer:
me
Step-by-step explanation:
1.326 grams of NH3 are required to produce 4.65 g of HF.
Step-by-step explanation:
Balanced chemical reaction is written first to know the number of moles taking part in original reaction.
NH3 +3 F2 ⇒3 HF + NF3
Given:
mass of HF = 4.65
First the number of moles of HF in 4.65 grams is calculated by using the formula:
number of moles (n) = 
atomic mass of HF = 20 grams/mole
putting the values in the above equation number of moles can be found.
n = 
= 0.235 moles of HF are given.
From the equation it can be said that:
1 mole of NH3 reacts to form 3 moles of HF
so, x moles of NH3 would react to form 0.235 moles of HF
= 
3x = 0.235
x = 
x = 0.078 moles of NH3 is required.
The moles are converted to mass by applying the formula:
mass = atomic mass X number of moles (atomic mass of NH3 = 17 grams/mole)
putting the values in the formula
mass = 17 X 0.078
mass = 1.326 grams
Nine less than a number
is
n - 9