175 mL at 25% concentration of alcohol contains 0.25 (175 mL) = 43.75 mL of alcohol. If <em>v</em> is the amount of the 70% solution that you use, then that amount contains 0.7<em>v</em> mL of alcohol.
Mixing these two yields a total volume of 175 mL + <em>v</em>, and it contains 43.75 mL + 0.7<em>v</em> alcohol. You want to end up with a concentration of 45%, which means the ratio of the amount of alcohol to the total volume needs to be 0.45:
(43.75 mL + 0.7<em>v</em>) / (175 mL + <em>v</em>) = 0.45
Solve for <em>v</em> :
43.75 mL + 0.7<em>v</em> = 0.45 (175 mL + <em>v</em>)
43.75 mL + 0.7<em>v</em> = 78.75 mL + 0.45<em>v</em>
0.25<em>v</em> = 35 mL
<em>v</em> = 140 mL
I'm not good with intigers, but if you added two negative intigers together wouldn't it still be negative? If you added -1 to -2 you'd get -3. It would always be less than the two original integers.
X = 42
x/3 - 4 = 10
+ 4 +4
x/3 = 14
•3 •3
x = 42
Answer:
22-18-25,
19-24-30,
7-24-25
Step-by-step explanation:
In a triangle with side lengths 
, 
, and 
, any two sides must have a sum larger than the third.
Using this rule, the possible side lengths out of these choices that could form a triangle are:
22-18-25,
19-24-30,
7-24-25
By hypothesis, Deon is riding at a speed of 22.4 kilometers per hour. So each hour, he completes 22.4 km.
If he rides for 7 hours, he completes 22.4 * 7 = 156.8 km
So in 7 hours, he rides 156.8 kilometers.
Hope this helps! :)
