Answer:
36x + 45
Step-by-step explanation:
given
9(3x + 5 + x) ← collect like terms inside parenthesis
= 9(4x + 5)
Multiply the terms inside the parenthesis by the 9 outside
= (9 × 4x) + (9 × 5)
= 36x + 45
It is given that the sample size is 17.
So degrees of freedom is 16.
The confidence level is 80%.
Use the t table or a tool to find the critical t value as below:
The one tail t value for 80 percent confidence is 0.865 using t table.
So the critical value is 0.865.
3.15 will be your answer i am very sure of that
They will have the same amount of money after 7 weeks.
We first set these equal to each other:
36+4x=x²+15
We want to gather all of the variables on one side. Subtract 4x from both sides:
36+4x-4x=x²+15-4x
36=x²-4x+15
We want the equation to be equal to 0 to solve it, so subtract 36 from both sides:
36-36=x²-4x+15-36
0=x²-4x-21
We can factor this expression. We want factors of -21 that sum to -4; -7(3)=-21 and -7+3=-4:
0=(x-7)(x+3)
Using the zero product property, we know that x-7=0 or x+3=0; this means x=7 or x=-3. Since a negative number of weeks makes no sense, the answer is 7 weeks.