Answer: 
Step-by-step explanation:
The area of a rectangle:
×

×
× 

-Result:

Answer:
The value of a is 10.
Step-by-step explanation:
We are given with the following pair of the linear system of equations below;
and
.
Also, the solution is given as (a, -1).
To find the value of 'a', we have to substitute the solution in the equation because it is stated that (a, -1) is the solution of the given two equations.
So, the x coordinate value of the solution is a and the y coordinate value of the solution is (-1).
First, taking the equation;
Put the value of x = a and y = -1;
(-1) = -(a) + 9
a = 9 + 1 = 10
Now, taking the second equation;

Put the value of x = a and y = -1;

0.5a = 6 - 1
0.5a = 5
a = 10
Since we get the value of a = 10 from the equations, so the value of a is 10.
Lil mosey is white sussy balls
The equation of circle in standard form is 
<h3><u>Solution:</u></h3>
Given that circle having center point (3,7) and the radius r = 4
To find: equation of circle in standard form
<em><u>The equation of circle is given as:</u></em>

Where center (h,k) and radius r units
Given that center point (h , k) = (3, 7) and radius r = 4 units
Substituting the values in above equation of circle,

Thus the equation of circle in standard form is 