Here is the equation:
Since both decimals are negative, the answer will be positive.
- Negative times Negative = Positive
Divide both sides by -3.9 to leave the variable alone:
r is equal to 4 → r = 4
Answer:
6/7
Step-by-step explanation:
Answer:
The original bill was $25.26
Step-by-step explanation:
To find the original bill, you need to divide the amount paid by the percentage paid. Since the tip was 21.5% on top of the full amount already, we know she paid 121.5%. So we can divide the cost by that.
$30.69/121.5% = $25.26
Answer:
Amount of NaCl = 23.376 gram
Step-by-step explanation:
Given:
Molarity = 4M
Volume of solution = 100 ml
Find:
Amount of NaCl
Computation:
Molar mass of Na = 22.99 g/mole
Molar mass of Cl = 35.45 g/mole
Molar mass of NaCl = 22.99 + 35.45
Molar mass of NaCl = 58.44 g/mole
Molarity = [moles of solute / volume of solute(ml)]1,000
4 = [moles of solute / 100]1000
Moles of solute = 0.4
moles of solute = Mass of solute / molar mass
0.4 = Amount of NaCl / 58.44
Amount of NaCl = 23.376 gram
