Answer:
See the image for solution.
Brainlist please
Let
x-------------> amount added <span>to each side
</span>A-------------> area increased----------> 84 ft²
we know that
A=(10+x)*(5+x)=84-----------> 10*5+10*x+5*x+x²
50+15x+x²=84----------> x²+15x-34=0
<span>solving the second order equation
</span>x1=-17
x2=2
the answer is x=2 ft
The value of a=7 will make the equation true
The equation of any given circle is:

where (h, k) is the center and r is the radius.
In the problem, we are given the center, and the radius. When we plug them in:

we got the formula of the circle.