(2x-3)(x+5)
Use foil to simplify, First multiply together the first terms of the pairs, then the outer terms, the middle terms, and finally the last terms. Then combine like terms.
2x^2+10x-3x-15 equals 2x^2+7x-15
"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!!
