Answer:
Step-by-step explanation:
26% is (26-20)/(50-20) = 6/30 = 1/5 of the way between 20% and 50%. That means 1/5 of the solution is 50% acid.
50% acid: 1/5 · 100 mL = 20 mL
20% acid: 100 mL -20 mL = 80 mL
Delbert must mix 80 mL of 20% acid and 20 mL of 50% acid.
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Maybe you'd like to see an equation. Let x represent the amount of 50% acid required. Then 100-x is the amount of 20% acid needed. The amount of acid in the mix is ...
0.50(x) +0.20(100 -x) = 0.26(100)
(0.50 -0.20)x = (0.26 -0.20)100 . . . . subtract 0.20(100)
x = (0.26 -0.20)/(0.50 -0.20)×100 = 20
This last expression should look a lot like the one we started with in this answer. It shows you how you can almost write down the answer to mixture problems without a lot of work.
Answer:
"All integers are irrational numbers" False
"No whole numbers are irrational numbers" True
"Some rational numbers are not integers" True
"Some integers are not whole numbers" True
Step-by-step explanation:
I'm 100% sure of this.
IF 9 IS ROUNDED TO THE NEAREST 10 IT WILL BE SO IF 9 THOUSHAND IS ROUNDAND TO THE NEAREST THOUSAND IT WILL BE 100 DONT WORRY ABOUT THE 755
Answer:
Step-by-step explanation:
The area of a trapezoid is given by the average of the bases multiplied by the height.
What we're given:
- Height of 3
- Bases of 1 and 4
The average of the bases 1 and 4 is equal to 
Therefore, the area of the trapezoid is 
Answer:
Let
x = number of yards mowed
The domain of the function is
5 ≤ x ≤ 20
If we multiply the inequality by 25, we get
125 ≤ 25*x ≤ 500
Which is the same as
125 ≤ f(x) ≤ 500
(Range of the function)
Domain 5 ≤ x ≤ 20
Range 125 ≤ f(x) ≤ 500
