number - n
Twice a number - 2n
Seven times the number - 7n
2n = 7n +35
7n-2n = -35
5n = -35
n = - 7
Check:
2(-7) = 7(-7) +35
-14 = -49 + 35
-14 = -14 True
The number is (- 7).
Answer : The cost of 10 balls will be, 13.5 dollars
Step-by-step explanation :
As we are given the following expression:

where,
P = total price (in dollars)
n = number of balls used
Given:
n = number of balls used = 10
Now we have to determine the cost of 10 balls.




Thus, the cost of 10 balls will be, 13.5 dollars
Answer:
Step-by-step explanation:
given that certain tubes manufactured by a company have a mean lifetime of 800 hours and a standard deviation of 60 hours.
Sample size n =16
Std error of sample mean = 
x bar follows N(800, 15)
the probability that a random sample of 16 tubes taken from the group will have a mean lifetime
(a) between 790 and 810 hours,
=
(b) less than 785 hours

, (c) more than 820 hours,

(d) between 770 and 830 hours
=
Hello there,
So we are trying to find out is the angle ∠BAC in degrees.
So what we are going to do is. . .25- (2x-10)°.
That answer would be -2x+35.
So ∠BAC= -2x+35°.Hope this helps.
~Jurgen