Answer:
20%
Step-by-step explanation:
- Set up a proportion:
- Cross multiply, then divide: 280 × 100 = 28000, 28000 ÷ 1400 = 20
- So, 20% were satisfied with their car
I hope this helps!
What is the solution to this system? Y=-5x+8,y=11/7x-4/7
1 answer:
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Last option is the correct answer.
Step-by-step explanation:
Given that
Let x stand for the solution a and y stand for the solution B
So,
According to statement that
30 gallons have to be made
Solution A contains 29 percent bromine => 0.29x
Solution B contains 53 percent =>0.53y
And the mixture of 30 gallons contains 45% bromine
Following equations will be used for solving the problem
Hence,
Last option is the correct answer.
Keywords: Equations, Variables
Learn more about linear equations at:
#LearnwithBrainly
Answer:
x = 2 cm
y = 2 cm
A(max) = 4 cm²
Step-by-step explanation: See Annex
The right isosceles triangle has two 45° angles and the right angle.
tan 45° = 1 = x / 4 - y or x = 4 - y y = 4 - x
A(r) = x* y
Area of the rectangle as a function of x
A(x) = x * ( 4 - x ) A(x) = 4*x - x²
Tacking derivatives on both sides of the equation:
A´(x) = 4 - 2*x A´(x) = 0 4 - 2*x = 0
2*x = 4
x = 2 cm
And y = 4 - 2 = 2 cm
The rectangle of maximum area result to be a square of side 2 cm
A(max) = 2*2 = 4 cm²
To find out if A(x) has a maximum in the point x = 2
We get the second derivative
A´´(x) = -2 A´´(x) < 0 then A(x) has a maximum at x = 2
