3x2(4x<span> – 3) + 1(4</span>x<span> – 3) </span>
Answer:
C. 40
Step-by-step explanation:
Let us say there are x 7's and y 77's.
We have been given that each term in the sum a1+a2+a3+...+an is either 7 or 77 and the sum equals 350. We are asked to find the value of n.
Since the sum of all numbers is 350, so we can represent this information in an equation as:

The only integer solutions for the equation
are 10, 20, 30, 40, 50
.
So, there can be these many terms: 10 or 20 or 30 or 40 or 50
.
The given option only contains 40, so 40 would be the answer. For 40 terms to be there, there has to be 39 sevens and 1 seventy-seven.
Let us verify our answer.




Therefore, the total terms (n) could be equal to 40 and option C is the correct choice.
The correct answer is the first option, y = 0.6x + 0.6. When the line of best fit is drawn, the slope can be solved by the formula m=Δy/Δx, where Δy is the difference between two y-coordinates and Δx the difference between two x-coordinates. The y-intercept is the value at which the line coincides with the y-axis (x=0).
If 60% purchase a stereo and 50% purchases tinted windows, then the percentage of people who purchased both have been counted twice. So we have to subtract 35% (the % that purchased both) from the sum of the first two percentages:
60% + 50% - 35% = 75%
Therefore, the probability that a customer picked up any one or both options (which is at least 1) is 75%.