PLS HELP THIS IS HARD

Find the sum of the first 8 terms of the following sequence. round to the nearest hundredth if necessary.

Adam plans to choose a video game from the section of the store where everything is 75% off. he writes the expression d-0.75d to find the sale price of the game if the original price is d dollars. gena correctly writes another expression, 0.25d, that will also find the sale price of the game if the original price is d dollars. use the drop down menus to explain each part of adams and rena's expression

Consider the input and output values for f(x) = 2x - 3 and g(x) = 2x + 7. what is a reasonable explanation for different rules with different input values producing the same sequence?