Answer:
- 750 mL of 0.23% solution
- 250 mL of 0.03% solution
Step-by-step explanation:
Let x represent the quantity (in liters) of the higher percentage solution, the 0.23% solution. Then 1-x will be the quantity of 0.03% solution. The amount of salt in the mix is ...
0.23%·x +0.03%·(1 -x) = 0.18%·1
Multiply by 100% and subtract 3:
20x = 15
x = 15/20 = 0.75 . . . . liters of 0.23% solution
1-x = 1-0.75 = 0.25 . . liters of 0.03% solution
The lab tech needs 750 mL of 0.23% solution and 250 mL of 0.03% solution.
$1235-$800=$435 thus the I which is the simple interest
:I=PRT all over 100
435=800(R) (5)all over 100
43500=4000R
:R=10.88%
Answer:
<h2>30</h2>
Step-by-step explanation:
<h3>to understand the steps</h3><h3>you need to know about:</h3>
- system of linear equation
- word problems
- PEMDAS
first step
let's create the equation word problem
<h3>my mother's current age is four times the sum of the ages of my two sisters. After 5 years, my mother's age will be double the sum of the ages of my two sisters. What is the current age of my mother? (imaginary problem)</h3>
let's solve
let my mother's and sister's age be x and y respectively
according to the first condition,x=4y....(I)
according to the 2nd condition,x+5=2(y+5×2).....(ii)
so the system of linear equations is
x=4y
x+5=2(y+5×2)
gets from the second equation
x+5=2(y+10)
x+5=2y+20
4y+5=2y+20 (as x=4y)
2y=15
y=7.5
so the age of mother is
x=4.(7.5)
x=30
Answer:
Step-by-step explanation:
What they are asking for here is where the y-values are negative in interval format. Intervals are x things only, no y's allowed. So the interval of (-infinity, -3) indicates an x value of negative infinity to an x value of -3. The y's are negative from an x value of negative infinity to an x-value of -3, then again from an x value of almost -1 to an x value of almost positive 1. So your choice is the last one listed there.
