The shape of a quartic with a negative leading coefficient most closely resembles what letter

M

Step-by-step explanation:

A quartic equation/function is a fourth degree polynomial. The general form is:

We can put any values for the variables a, b, c, d, and e.

The general shape of a fourth degree polynomial is in the shape of the English letter "W".

The leading coefficient is the value of "a".

If a is negative, the curve gets upside down, so a "W" going upside down would resemble an "M".

A graph of a quartic with negative leading coefficient is shown attached. The equation is:

a 4/6 = 9/12   not proportional

step-by-step explanation:

to find which are not proportional, we can use cross products

if it is true, they are proportional.   if it is not true, they are not proportional.

a 4/6 = 9/12

4* 12 = 6*9

48 = 54

not this is not proportional  

b 2/3 = 12/18  

2* 18 = 3 * 12

36 = 36

this is proportional

c 5/4 = 10/8  

5*8 = 4*10

40 = 40

this is proportional

d 7/5 = 35/25

7*25 = 5 * 35

175 = 175

is proportional