Answer:
x=-1
Step-by-step explanation:
4x-16=-20
Get x to one side by subtracting it.
-16=-20-4x
Add the 20 on both sides.
-16+20=-4x
Simplify
4=-4x
4/-4=-4x/-4
-1=x
x=-1
Answer:
185/24
Step-by-step explanation:
Convert both to fractions with the same denominator first.
35/8= 105/24
10/3= 80/24
105/24+80/24
= 185/24
Answer:
1/5
Step-by-step explanation:
5/5 - 4/5 = 1/5
When you multiply by 10, 100, or 1000, you must move the decimal place over by how many zeroes there are. Once there is no more decimals, you add 0's to the end of the number until you are done.
For example, 5.6 x 1000
1000 has 3 zeroes.
That means we need to move the decimal spot 3 times.
5.6 x 1000 = 56 x 100
We got rid of the decimal but we still have 2 zeroes left. So now we just add 2 zeroes at the end of the number.
5.6 x 1000 = 56 x 100 = 5600
I hope that helps! :)
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.
_____
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.
