Answer:
7.5 L of 10% solution and 22.5 L of 30% solution
Step-by-step explanation:
Volume of 10% solution plus volume of 30% solution = total volume of 25% volume.
x + y = 30
Acid in 10% solution plus acid in 30% solution = total acid in 25% solution.
0.10 x + 0.30 y = 30 × 0.25
0.10 x + 0.30 y = 7.5
Solve the system of equations, using either substitution or elimination. I'll use substitution:
x = 30 − y
0.10 (30 − y) + 0.30 y = 7.5
3 − 0.10 y + 0.30 y = 7.5
0.20 y = 4.5
y = 22.5
x = 30 − y
x = 7.5
Sarah needs 7.5 L of 10% solution and 22.5 L of 30% solution.
Answer:

Step-by-step explanation:
We can start by finding the third side of the triangle/the side of the square using the Pythagorean Theorem:

In this case the side length of the square would be represented by the variable "c" as it is the hypotenuse:




Since the area of a square is the side length square then...

The square root and the squared cancel out giving us...

The equation of the central street PQ is -1.5x - 3.5y = -31.5 option (b) is correct.
<h3>What is a straight line?</h3>
A straight line is a combination of endless points joined on both sides of the point.
We have a straight line:
Convert it to the general form given below:

or

(Slope of AB line)
For the slope(m') of the PQ line:
( because AB and PQ are perpendicular to each other)

We know the:

Where (x', y') = (7, 6), we get:


(multiply by -1/2 on both sides)
Thus, the equation of the central street PQ is -1.5x - 3.5y = -31.5
Learn more about the straight line.
brainly.com/question/3493733
Width : Length
2 : 3
Perimeter = 2* width + 2*length
Ratio becomes:
Width : Length
4 : 6
Total units = 4 + 6 = 10
Perimeter = 40
Answer: Width is 8 ft and Length is 12 ft.
Answer:
x = 2 11/12
Step-by-step explanation:
Multiply the equation by 12. This eliminates fractions.
... 12 -12x -28 = 12x +27 -36x -8
Collect terms.
... -16 -12x = -24x +19
Add 24x+16
... 12x = 35
Divide by the coefficient of x
... x = 35/12 = 2 11/12