Answer:
Step-by-step explanation:
let x,y be the sides of court.
2(x+y)=90
x+y=90/2=45
y=45-x
xy=500
x(45-x)=500
45x-x²=500
x²-45x+500=0
x²-25x-20x+500=0
x(x-25)-20(x-25)=0
(x-25)(x-20)=0
x=25,20
when x=25
y=45-x=45-25=20
when x=20
y=45-20=25
sides are 25 ft,20 ft.
Answer:
c is the answer
Step-by-step explanation:
i ust know
First substitute .5x in for y to get a solvable equation. You should get 6x+8(.5x)=30. Then multiply 8 times .5 to get 6x+4x=30. Then combine like terms (6x+4x) to get 10x=30 and divide both sides by 10 to get x=3. Then plug this x value (3) into the other equation (y=.5x) to find the value of y. Y=.5(3) so y=1.5. Therefore the answer is B.
Answer:
Answer is after 20 miles
Step-by-step explanation:
10 +2.5x = 3x
10 = 3x-2.5x
10=0.5x
10/.5=x
x=20
At 20 miles they both have a cost of 60
To get rid of

, you have to take the third root of both sides:
![\sqrt[3]{x^{3}} = \sqrt[3]{1}](https://tex.z-dn.net/?f=%20%5Csqrt%5B3%5D%7Bx%5E%7B3%7D%7D%20%3D%20%5Csqrt%5B3%5D%7B1%7D%20)
But that won't help you with understanding the problem. It is better to write

as a product of 2 polynomials:

From this we know, that

is the solution. Another solutions (complex roots) are the roots of quadratic equation.