Martin and his family ate in a restaurant. the cost of the food was $84. including the tip, martin paid $100.80. how much was the tip?

$16.80

Step-by-step explanation:

This is a simple subtraction problem!

Steps:

1. 100.80-84= 16.80

--subtract how much the bill was from how much he paid to find out how much he tipped.

The tip was $16.80!

Hope this helped :)

i dont get it. where are the "descriptions"?

x= -3 and

step-by-step explanation:

to find the roots of a cubic, use division or factoring to find the factors then set equal to 0. as this is a difference of cubes, it factors into

where a is the cube root of .

here   this is 27 and the cube root of 27 is 3. so we write using the form:

.

set each factor to 0 and solve for x.

x-3=0

x=3

the quadratic expression does not factor and must be solved using the quadratic formula.

where a = 1, b=3, and c=9

this cubic has two complex roots.