For f(x) = 3x + 1 and g(x) = x ^ 2 - 6 , find (fg)(4)

Which is the equation of an ellipse with directrices at x = ±4 and foci at (2, 0) and (−2, 0)?

Out of $20$ creepy-crawly creatures in a room, $80\%$ are flies and $20\%$ are spiders. if $s\%$ of the total legs belong to spiders, what is $s$?

Which of the following is best modeled using a linear equation y=ax+b, where a is less than 0?