Find the general solution for the differential equation \displaystyle{\left.{d}{y}\right.}+ {9}{x}\ {\left.{d}{x}\right.}={0}dy+9x dx=0 cc, a constant of integration

y= CC-4.5x^2

Step-by-step explanation:

To find the general solution to the differential equation

dy + 9x dx = 0, we employ the method of separating variable as follows:

Note: { will represent the integral sign here.

Separating the variables and integrating, we have

{dy  = -{9x dx

y = -(9/2)(x^2) + CC,

where CC is the given constant of integration.

This can be rearranged/simplified to yield

y= CC-4.5x^2

distance covered by pamela in 9 l of fuel = 99km

let us apply unitary method here.

distance covered by pamela in 1 l of fuel =99/9 =11 km

now let us find distance covered by pamela if she has 12 l of fuel.

distance covered in 12 l = distance covered in 1 l of fuel * 12

we know that distance covered by here in 1 l is 11 km.

so distance covered in 12 l of fuel = 11*12 = 132 km.

(b) 240

step-by-step explanation:

first, we use the pythagorean formula using the given side lengths to find x. then we use x to find the side lengths. then we add the side lengths to find the perimeter.

pythagorean theorem formula:

a^2 + b^2 = c^2

(x - 20)^2 + (x - 40)^2 = x^2

x^2 - 40x + 400 + x^2 - 80x + 1600 = x^2

x^2 -120x + 2000 = 0

(x - 100)(x - 20) = 0

x - 100 = 0 or x - 20 = 0

x = 100 or x = 20

we see that the solution x = 20 must be discarded because it will give a negative side length and a side length of 0. the only valid solution is x = 100.

perimeter = sum of the lengths of the sides

perimeter = x + x - 20 + x - 40

perimeter = 3x - 60

replace x with 100.

perimeter = 3(100) - 60

perimeter = 300 - 60

perimeter = 240