If Sandra mixes <em>x</em> L of 65% solution with <em>y</em> L of 90% solution, then the resulting mixture has a total volume of
<em>x</em> + <em>y</em> = 500
litres, and it contains
0.65<em>x</em> + 0.90<em>y</em> = 0.75 (500) = 375
litres of alcohol.
Solve the first equation for <em>y</em> :
<em>y</em> = 500 - <em>x</em>
<em />
Substitute this into the second equation and solve for <em>x</em> :
0.65<em>x</em> + 0.90 (500 - <em>x</em>) = 375
0.65<em>x</em> + 450 - 0.90<em>x</em> = 375
75 = 0.25<em>x</em>
<em>x</em> = 300
Solve for <em>y</em> :
<em>y</em> = 500 - 300
<em>y</em> = 200
So, Sandra should mix 300 L of 65% solution with 200 L of 90% solution.
60 because all of the sides are equal
I really dont understant your question. but you are right that negative 8 that it would be minus. <span>In </span>mathematics<span>, a </span>negative<span> number is a real number that is less than zero. </span>Negative<span> numbers represent opposites. If positive represents movement to the right, </span>negative<span> represents movement to the left.</span>
Steps to solve:
1/2hb = d²
~Divide 1/2h to both sides
b = 2d²/h
Best of Luck!
Answer:
25
Step-by-step explanation:
Given the model:
y=−3.5x+400
Number of children in amusement park = y
Temperature = x
On a certain day:
Temperature = 90°F
Number of children in park = 60
Using the model :
The predicted number of children in park when temperature is 90°F would be :
y = - 3.5(90) + 400
y = - 315 + 400
y = 85
Model prediction = 85 children
Actual figure = 60
Residual :
|Actual - predicted | = |60 - 85| = 25 children
