Ten pipes can drain a pool in 2 hours. If only 4 pipes are used, how
1 answer:
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Answer: k = -1 +/- √769
<u>Step-by-step explanation:</u>
48x - ky = 11
<u>-48x </u> <u> -48x</u>
-ky = -48x + 11
Slope:
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(k + 2)x + 16y = -19
<u>- (k + 2)x </u> -<u>(k + 2)x </u>
16y = -(k + 2)x - 19
Slope:
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and
are perpendicular so they have opposite signs and are reciprocals of each other. When multiplied by its reciprocal, their product equals -1.
*
= -1
= 1
Cross multiply, then solve for the variable.
(k + 2)(k) = 16(48)
k² + 2k - 768 = 0
Use quadratic formula to solve:
k = -1 +/- √769
Answer:
C: (-8,3) R:5
Step-by-step explanation:
The equation of a circle can be written as:
(x-h)^2+(y-k)^2=r^2
where (h,k) is the center, and r is the radius
We have the equation:
(x+8)^2+(y-3)^2=25
Center:
The center is (-8,3)
(x+8)^2--> (x-h)^2
Therefore the x coordinate of the center is -8
(y-3)^2-->(y-k)^2
Therefore the y coordinate of the center is 3
Radius
r^2=25
Take the square root of both sides
r=5