Question

The difference between two positive numbers is 7 and the difference between thes
cubes is 805. If 'A' represents their product and 'B' represents the sum of their squares,
find the value of 'A-B'.​

Answer 1

Step-by-step explanation:

let the two numbers be x and y

according to condition

x-y=7

x^3-y^3=805

A=product of x and y=xy

B=sum of squares=x^2+y^2

(x-y)(x^2+y^2+xy)=805

x^2+y^2+xy=805/7=115

therefore,A+B=115(this is your first equation)

square on both sides of x-y

therefore, x^2-y^2=7^2

therefore,x^2+y^2-xy=49

B-2A=49

subtract 2 from 1

(B+A)-(B-2A)=115-49

3A=66

A=22

And

22+B=115

therefore,B=115-22=93

Hence,A-B=22-93=-71

Hope it helps you zombie.

have a good night

Answer 2

$\huge\bf\color{blue}{solution}$

When path built then the new radius

become = 42+3.5 = 45.5m

Now

Cost = Area×Rate

Let the old radius be 'r' and new radius be 'R'

Area of the garden

π(R² - r²)

22/7(45.5² - 42²)

22/7 × (2070.25 - 1764)

22/7 × 306.25

9625m.

Now

Cost = Rrea× Rate

Cost = 962.5×20

Cost = 19250