8 litres (amount of 20% solution needed) and 7 litres for (amount of 50% solution needed)
<u>Step-by-step explanation:</u>
Let consider ‘x’ for 20% acid solution and (15 – x) for 50% acid solution. And so, the equation would be as below,
20% in x + 50% in (15 – x) = 15 litres of 34%
Convert percentage values, we get
0.20(x) + 0.50 (15 – x) = 15 (0.34)
0.20 x + 7.5 – 0.50 x = 5.1
-0.3 x + 7.5 = 5.1
0.3 x = 7.5 – 5.1
0.3 x = 2.4

Apply ‘x = 8’ value in (15 – x) we get,
15 – 8 = 7 litres
The value of 7 litres for (amount of 50% solution needed)
Answer:
-2
Step-by-step explanation:
First, you need to find the equation.
f(x) = -3x + b
Now we need to find the y-intercept.
f(x) = -3x + b
f(-9) = -3(1) + b
-9 = -3 + b
-6 = b
f(x) = -3x - 6
The zero of f means that f(x) = 0
f(0) = -3x - 6
f(6) = -3x
x = -2
Well if the window is 40 x 10 the L is 52 and the w 22
5). Radius = 6 km. Circumference = 12π km. Area = 36π km²
6). Diameter = 8 mm. Circumference = 8π mm. Area = 16π mm²
We do like the following:
Set the first number is a and the second is b.
We have two equations: a+2xb=24, 2xa+b=21
And we have 2xa+4xb=48 or 2xa=48-4xb
So: 48-4xb+b=21 or -3xb=21-48=-27 and we got b=-27:(-3)=9 and a= 6
a=6 and b=9