Answer:
9
Step-by-step explanation:
Compare your x2 + y2=81 to the following:
x^2 + y^2 = 81
The " ^ " symbol indicates exponentiation.
Now compare x^2 + y^2 = 81 to
x^2 + y^2 = r^2.
This is the standard equation of a circle of radius r centered at the origin, (0,0). You can see for yourself that 81 must equal r^2.
Taking the square root of 81, we get plus or minus 9.
But the radius must be positive, so we reject the -9 and take +9.
The radius is 9.
Okay the answer is 69 because 81-2 is 69
Answer:
i think D
Step-by-step explanation:
Answer:
5c^2 +6c +13
Step-by-step explanation:
so we can see than 5c^2
and 13c - 7c are the same = 6c
and 4 +9 = 13
so answer will 5c^2 +6c +13
Answer:
Line s and Line t are parallel.
Step-by-step explanation:
Now, we know that angles 1 and 2 are congruent, because they have the same angle measures. Now, looking at their positions, we can see that they are alternate exterior angles.
By the converse of the Alternate Exterior Angle, (I do not remember exactly how the theorem went) if two lines are cut by a transversal and have congruent alternate exterior angles, then the lines are parallel. Using this theorem, we can find that lines s and t are parallel, because they are cut by a transversal and their alternate exterior angles are congruent.
I hope you find my answer and explanation to be helpful. Happy studying.