16.64 average of the four races that kerri ran in seconds.
Answer:
Width of the arch = 105 m
Step-by-step explanation:
Function representing the width of the arch,
f(x) = -0.016(x - 52.5)² + 45
where x = width of the base of the arch or horizontal distance from arch's left end
f(x) = vertical distance of the arch
From the given quadratic function, vertex of the parabola is (52.5, 45).
Coordinates of the vertex represents,
Height of the arch = 45 m
Half of the horizontal distance from the left end = 52.5 m
Therefore, width of the bridge = 2(Half the width of the bridge from left end) = 2×52.5
= 105 m
Therefore, given bridge is 105 m wide.
Answer:
D. There is no association because the distribution of lunch preference is approximately the same among the pet groups.
The second system of equations,

is correct.
We know that Bethany's age is x. Since Laura is 13 years older, her age is x+13. The product of their ages is equal to twice Amanda's age, and Amanda's age is y. This gives us:
x(x+13) = 2y
Using the distributive property, we have
x²+13x=2y
Dividing everything by 2 (to isolate y), we have:
x²/2 + (13/2)x = y
If we take 20 years off of Bethany's age, it is now represented as x-20. Taking 20 years off of Laura's age would be (x+13-20) or x-7. The product of their ages now is equal to David's age; David is 11 years older than Amanda, so his age is y+11. This gives us:
(x-20)(x-7)=y+11
Multiplying the binomials we have:"
x*x - 7*x - 20*x - 20(-7) = y+11
x²-7x-20x--140=y+11
x²-27x+140=y+11
To isolate y, subtract 11 from both sides:
x²-27x+140-11 = y+11-11
x²-27x+129 = y
-4 is the slope in the equation