Li needs 15 pieces of string each 1/2 of a inch long . She cut a 6 inch piece of string into pieces that are each 1/2 of an incch long . How many more pieces of string does she need?

3 pieces

Step-by-step explanation:

string length = 6 inch

6 inch ÷ 1/2 = 12 pieces

remaining :

15 - 12 = 3 pieces

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.

b. 153 students do not participate in sports and seventy-five 12th graders were surveyed