The second one is D,
the third one is C
and the 4th one i don't know sorry
Hope this helps :D
The general equation of a line is y = mx + b
m is given as 1/2, so we have:

Plugging in the given values of x and y, we get:
-2 = 0 + b
Therefore b = -2, and the answer is:
BEST estimate of this amount is
. Correct option A. 2 x 10^7 .
<u>Step-by-step explanation:</u>
Here we have , Hoover Dam spans the Colorado River on the Nevada-Arizona state line. For its construction, the federal government purchased 21,670,000 pounds of gates and valves. We need to find BEST estimate of this amount . Let's find out:
21,670,000 pounds
⇒ 21,670,000 pounds
⇒ 
⇒ 
⇒ 
⇒ 
⇒ 
Now, Rounding of 2.167 we get 2 ,So
⇒ 
Hence , BEST estimate of this amount is
. Correct option A. 2 x 10^7 .
False ..................................