Answer:
m/(1 - .8)
Step-by-step explanation:
She read 80% of her emails, which is .8 of the total. So her unread emails would be 100% - 80% = 1 - .8
that means me can be written as:
m = (1 - .8)t
where t is the total
If we solve for t, we get:
t = m/(1 - .8)
Answer:
$6.50 per bag of popcorn
Step-by-step explanation:
let a bag of popcorn be represented by p and a candy bar be b
28p + 40b= $282
17p + 20b= $160.50
this is an example of stimatanelous equations
so you have to double the second equation to give 34p + 40b =$321
subtract the equations to give one
6p =$39
divide $39 by 6 to give the value of one bag of popcorn = $6.50
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
Answer:
ASA (the third choice)
Step-by-step explanation:
The pictures show that they have 2 angles congruent, plus the side between the 2 angles.