Answer:
D. 21 ft
Step-by-step explanation:
We need to use Power of Points, which basically says that for intersecting chords in a circle (see attachment), a * b = c * d.
Here, we can say that a = x, b = 6, c = 7, and d = 18. Then, we have the equation:
ab = cd
x * 6 = 7 * 18
6x = 126
x = 21
Thus, x is 21 ft.
Hope this helps!
Answer:
C, 45 degrees
Step-by-step explanation:
Ben's estimate gives 7 g of nickel; the actual amount is 8.03 g.
In 1 g of the substance, there is 0.52 g of copper and 0.25 g of zinc; this gives
0.52+0.25 = 0.77 g of the substance.
The remaining part of the substance is nickel:
1-0.77 = 0.23 g of nickel.
Using Ben's estimate, 0.2 g of nickel per gram of substance, we have
0.2(35) = 7 g of nickel in 35 g of the substance.
The actual amount is 0.23(35) = 8.03 g of nickel in 35 g of the substance.
So, first, what are the two sides?
let's call then x and y
we know that 2(x+y)=12.5 (that's the distance around)
so that means that x+y=6.25 (I just divided both by 2)
now, x=4y (from "4 times as long as it is wide")
so we can substitute:
x+4x=6.25
5x=6.25
x=1.25
so one side, is 1.25 and the other will be 1.25*4=5
and for the area we multiply the two:
1.25*5=6.25 square kilometers, and this is the answer!
Answer:
Step-by-step explanation:
perp. -5
y + 7 = -5(x - 4)
y + 7 = -5x + 20
y = -5x + 13