Two different age groups were surveyed about the amount of time they spent on social media.
The results are shown in the two frequency
polygons below. The same time intervals were
used for both graphs.
11-year old students
15-year old students
a) How many 15-year old
801
80+
students took part in
70
70
the survey?
60
60
50
250
b) How many more 15-year
8:40
840
old students than 11-year
L 30
30
old students spent
20
20
between 35 and 45 mins
10
10
on social media?
0
0
0 10 20 30 40 50 60 70 80 0 10 20 30 40 50 60 70 80
(1)
Time (mins)
Time (mins)
Total marks: 2
Frequency

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.

hard

step-by-step explanation:

i saw this question before, dont know the asnwer srry

step-by-step explanation: