Answer:
see explanation
Step-by-step explanation:
To calculate the first 3 terms substitute n = 1, 2, 3 into the n th term formula
(a)
8 - 1 = 7
8 - 2 = 6
8 - 3 = 5
The first 3 terms are 7, 6, 5
(b)
The first negative term wii occur when n > 8, that is n = 9, thus
8 - 9 = - 1 ← first negative term
like 10????? i dont understand that much but i tryed
So pretend weekend calls is x and weekday calls are y.
the formulas is x + y = 610
0.07x + 0.08y = 48.05
So, x = 610 - y
Then, substitute x into the second equation.
0.07(610 - y) + 0.08y = 48.05
42.7 - 0.07y + 0.08y = 48.05
0.01y = 5.35
y = 535
Then substitute y into the first equation.
x + 535 = 610
x = 75
Just to be sure, substitute x and y into the second equation.
0.07(75) + 0.08(535) = 48.05
5.25 + 42.80 = 48.05
48.05 = 48.05
So, on weekends, he used 75 minutes.
On weekdays, he used 535 minutes.
It’s the last one because yeah
