If you know that b=0, then ab=bc doesn't tell you anything about
'a' or 'c', because no matter what they are, it's always true.
Answer:
natural numbers and integers
Answer:
She has 42 pieces of wood each of 1 inch of length.
Step-by-step explanation:
Amy has 42 inches piece of wood.
She has to cut an inch.
After cutting pieces of inch each she counts the pieces to be 42.
Mathematically
Total length / unit lenght = Number of pieces
42 inches/ 1 inch= 42 pieces.
She has 42 pieces of wood each of 1 inch of length.
<span>Dr. Graham currently has two acid solutions.
60% acid AND 20% acid </span>
Dr. Graham needs 30 L of a 50% acid solution
We set up 2 equations in which s = 60% acid and t = 20% acid
A) s + t = 30
B) .60s + .20t = (.50 * 30)
We multiply equation A by -.20
A) = -.20s -.20t = -6 then we add it to B)
B) .60s + .20t = 15
.40s = 9
s = 22.5
t = 7.5
So, she needs to mix 22.5 liters of 60% acid with 7.5 liters of 20% acid.
Source:
http://1728.org/mixture.htm
Answer:
The labor fee is $14.25, each quart of oil costs $2.25.
Step-by-step explanation:
Let $x be thee price of each quart of oil and $y be a flat fee for labor.
1. If the oil change for one car required 5 quarts of oil, then these 5 quarts cost $5x and together with a flat fee for labor it cost $25.50. Thus,
5x+y=25.50.
2. If the oil change for another car required 7 quarts of oil, then these 7 quarts cost $7x and together with a flat fee for labor it cost $30.00. Thus,
7x+y=30.00.
3. Subtract from the second equation the first one, then
Substitute it into the first equation:
The labor fee is $14.25, each quart of oil costs $2.25.
