Answer:
Explanation:
the answer
the true answer is A) 4x^2+52x+165=320; x = 2.5
proof:
since they want to limit its area to 320 in^2
x must be equal 2.5, because 4.(2.5)^2+52(2.5)+165= 25+130+165=320;
the main rule of the area of a triangle is
A= (base x height )/2
let be b the base and h the height
so h=20- 6b
so 50= b x( 20-6b) /2, implies 100/b = 20 - 6b
if b=x, we have 100= 20x -6x² this is equivalent to 6x² - 20x = -100
so the answer is
D) None of the choices are correct.
the largest dimensions that can be used for the fountain are
B) x^2+8x+16=800
C) x^2+16=800
proof
x^2+8x+16=x^2+8x+4², 4² is the area of the square fountain, and x^2+8x should be the remaining of the area, the total space that the fountain and sidewalk can use is 800, it is less than 800 ft^2.
Use the same method for. x^2+16=800