Im pretty sure its a and c but if it cant be both of them then u or ur teacher probably wrote one of them wrong
The common difference is x
the first term is x+1
a_8 = x+1 + x(8-1) = x+1 + 7x = 8x + 1
So when you are trying to find the solution to the system of equations make sure that you have it where y= -4/5x-6 and y= -30 are written like this:
-30=-4/5x-6
And then solve for x:
Add 6 on both sides.
-24=-4/5x
Then multiply by the reciprocal of -4/5.
-5/4*-24=-5/4*-4/5x
x=30
But then you are gonna want to plug 30 in for x in y=-4/5x-6 to make sure that it is the same as y=-30.
60+-90x would be equivalent.
Lets day the original price of the dvd player was $100,
36% marked down means you pay $64x
64x = $41.60
100x = 100/54 x 41.60 = 4160/64 = #65.00 = original cost
similarly, stereo tuners = 100/78 x 69.42 = 6942/78 = $89 original cost
DVD = 65- 41.60 = $ 23. 40 less
Stereo = 89- 69.42 = $ 19.58 less
Diffrence is $ 3.82
so your answer is the dvd player price was reduced by $3.82 more than the stereo tuner.
