The correct answer is D
The equation of a circle is (x-h)^2 + (y-k)^2 = r^2
to find (h,k), you find the middle of the circle, in this scenario you do so by finding the middle of the diameter, a line that goes through the center of the circle.
To find the X value of the midpoint, add both x values together and divide by 2 and repeat for y
-13 + -1 = -14
-14/2 =-7
10+ -6 = 4
4/2 = 2
therefore (h,k) = ( -7, 2 )
Next plug these values in the equation of a circle
(x-h)^2 + (y-k)^2 = r^2
becomes
(x- (-7)) ^2 + (y-(2)) ^2 = r^2
to find r, use the distance formula to find the length of the diameter, 20, and divide by 2
plug 10 in for r and you get 100
(x+7)^2 + (y-2)^2 = 100
sorry for the late response
Again, nice problem. These are not super easy. You need to imagine the triangles in the figure and relate sides.
For instance: ADC, its hypotenuse is 15
For ABC, it is 20,
so 20/15 is the ratio between both triangles. Now let's choose the side with 'x'
x is one side of ADC, the corresponding side in ABC is 15 (the second longest sides). You need to rotate the triangles, etc ... That's the tricky part :)
So:
20/15 =15/x ----> x = 15*15/20 = 225/20 = 45/4
Which is C
Not sure whether it's too late to help you though!!!!
Also notice that it's kind of a product rule:
x * 20 = 15 * 15
I am sure the book explains a short way of getting to this equation, like sides opposite, blah blah, but what i told you is the reason. You asked for understanding it! Best luck!
Answer:
Below
Step-by-step explanation:
● x^2 + 11x + 121/4 = 125/4
Substract 125/4 from both sides:
● x^2 + 11x + 121/4-125/4= 125/4 -125/4
● x^2 + 11x - (-4/4) = 0
● x^2 +11x -(-1) = 0
● x^2 + 11 x + 1 = 0
This is a quadratic equation so we will use the determinanant (b^2-4ac)
● a = 1
● b = 11
● c = 1
● b^2-4ac = 11^2-4*1*1 = 117
So this equation has two solutions:
● x = (-b -/+ √(b^2-4ac) ) / 2a
● x = (-11 -/+ √(117) ) / 2
● x = (-11 -/+ 3√(13))/ 2
● x = -0.91 or x = -10.9
Round to the nearest unit
● x = -1 or x = -11
The solutions are { -1,-11}
Answer:
-4(8-3x)>or =6x-8
Step-by-step explanation:
open d bracket
-32+12x >or = 6x-8
collect like terms
12x-6x >or =-8+32
6x = 24
divide both sides by 6
x= 4
