Substitute y=4x to the second equation:
x^2 + (4x)^2 = 17
x^2 + 16x^2 = 17
17x^2 = 17
x^2 = 17/17
x^2 = 1
x = 1 and -1
When x=1, y=4(1) = 4
When x=-1, y=4(-1) = -4
Thus the solutions would be (1,4) and (-1,-4). That would correspond to D. and A.
Answer:
5.19
Step-by-step explanation:
Answer:

or

Step-by-step explanation:
we know that
Applying the Pythagorean Theorem in the rectangular pool

where
d is the diagonal of the pool
L is the length of the pool
W is the wide of the pool
we have

substitute the given values

solve for L

simplify

or

The radius is 8 because its half the diameter.
Answer:
6
Step-by-step explanation:
Arc length = radius * central angle
s = rθ
A circle is 2π radians, so 1/3 of that is 2/3 π.
Given that s = 12 and θ = 2/3 π:
12 = r (2/3 π)
r = 18/π
r ≈ 6