Number 4
6=2•6-6
-18=-2•6-6
I think your answer is 78 = x -2
Answer:
C or d
Step-by-step explanation:
mean = (sum of values) / (number of values)
we know mean is 13 and we are given 8 values. The ninth value is the missing x:
13 = ((sum of 8 values) + x)/9
13 = (12+10+15+12+13+15+11+15+x)/9
13*9 = 103+x
x = 14
The missing value is 14. There are 14 pillows in the last box.
Let
x---------> first positive integer
x+1------> second positive integer
x+2-----> third positive integer
we know that
(x+1)*(x+2)=72-------> x² +2x+x+2=72 -------> x² +3x-70=0
using a graph tool-------> <span>I solve the quadratic equation
</span>see the attached figure
the roots are
x1=-10
x2=7
the answer is
first positive integer is x=7
second positive integer is x+1=8
third positive integer is x+2=9