It wouldn't let me post, so I screenshotted:
Answer:
Step-by-step explanation:
Length = L.
Width = 2L-3.
A = L * W = 170.
L * (2L-3) = 170.
2L^2 - 3L - 170 = 0,
L = (-B +- Sqrt(B^2-4AC))/2A.
L = (3 +- Sqrt(9 + 1360))/4,
L = (3 +- 37)/4 = 0.75 +- 9.25 = 10, and -8.5. In.
Use positive value: L = 10 In.
D would be the highest value
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.
