Answer:
hi........................................
Area of a circle using the radius is pi*r^2, so:
A=3.14*4^2
A=3.14*16
A=50.24
Given equation is y=2x+7 and 
Let's simplify the 2nd equation
before we can start graph so that calculation will be easy

multiply both sides by 2 to cancel out fractions

y=2x+7
which is exactly same as the first equatoin so graph of both will be exactly same and solution will be infinitely many solutions.
y=2x+7 has y-intercept 7 so first point will be (0,7). Slope is 2 so rise 2 unit up then 1 right and graph the new point.
Answer:
D
Step-by-step explanation:
Tell me if i am wrong
Answer:
<em>(x - 2)^2 + (y + 1)^2 = 26</em>
Step-by-step explanation:
A circle with center O(2, -1) that passes through the point A(3, 4).
=> The radius of this circle is OA which could be calculated by:
OA = sqrt[(3 - 2)^2 + (4 - (-1))^2] = sqrt[1^2 + 5^2] = sqrt[26]
The equation of a circle with center O(a, b) and radius r could be written as:
(x - a)^2 + (y - b)^2 = r^2
=> The equation of circle O above with center O(2, -1) and radius = sqrt(26) is shown as:
(x - 2)^2 + (y - (-1))^2 = (sqrt(26))^2
<=>(x - 2)^2 + (y + 1)^2 = 26
Hope this helps!