45 Degrees on each side means it is equal, for an "equilateral" triangle.
"T<u>he function is decreasing":</u>
This means the slope of the function will be negative at the given point. Anywhere the line is going down, from left to right, is decreasing. This eliminates choices A and C.
<u>"The function is concave down":</u>
This means the curve of the function will be open down (think of an upside down u). This eliminates choice E.
<u>"f(x)>0":</u>
This is anywhere the curve is above the x axis. This eliminates choice D.
The answer is Choice B) x=2.
Hope this helps!!
The best way to estimate it is to do "written addition" in your head, adding 1+8, then 9+3, all the way until you get to the front. the actual answer is 189,459, so your answer should be somewhere close to that.
The answer it 1. is A.
The answer to 2. is B.
About 1.83. You would set up the equation like this