What is the best estimate for the width of your index finger

For f(x)=2x+1 and g(x)= x^2 -7, find (f•g)(x)

What is the radical expression that is equivalent to the expression 27 1 over 5?

The figure shows triangle def and line segment bc, which is parallel to ef: triangle def has a point b on side de and point c on side df. the line bc is parallel to the line ef. part a: is triangle def similar to triangle dbc? explain using what you know about triangle similarity. part b: which line segment on triangle dbc corresponds to line segment ef? explain your answer. part c: which angle on triangle dbc corresponds to angle f? explain your answer. asap