Answer:
y = -1
Step-by-step explanation:
A horizontal line is of the form
y =
The y coordinate of the point (-2,-1) is -1
The equation is y = -1
The amount of substance left of a radioactive element of half life,

after a time, t, is given by:

Given that <span>potassium-40 has a half life of approximately 1.25 billion
years.
The number of years it will take for 0.1% of potassium-40 to remain is obtained as follows:

Therefore, </span><span>the maximum age of a fossil that we could date using 40k is
12.5 billion years.</span>
Answer:
The answer is the 1st one.
Step-by-step explanation:
Hope it helps! :)
Answer:
98 yards
Step-by-step explanation:
The new width is 40 yds + 2 yds = 42 yds.
Area = L × W
4200 square yds = L × 42 yds
L = 4200 yds ÷ 42 yds = 100 yds
The new length is 100 yds.
The old length = the new length - the width of the path × 2 = 100 yds - 1 yd × 2 = 100 yds - 2 yds = 98 yds.
The length of the park was 98 yds, before the path was built.