Can you please help me -2.5x + 6 + 30x - 4.5

How many zeros does the function f(x)=4x3-x2+1 have

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

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