Where S is sales price,
S = .75d
You said which expression CANNOT be used, but I assume you mean can. Let me know if you didn’t.
Well you could do 5(60x+20y), 100(3x+y), and 2(150x+50y)
Answer:
14 length of the side is 3x-7
and 15 length of side is 2x+6
bearing in mind that 9 months is not even a year, but since there are 12 months in a year, then 9 months is really 9/12 years.


Answer:
The answers would be as follows:
3
3
1
1
Step-by-step explanation:
We can tell that the first two have an infinite number of solutions because when we try to solve, we get a true statement. The first one is done for you below.
-6x + 7 = -6x + 7 ------> Add 6x to both sides
7 = 7 (TRUE STATEMENT)
We can tell the next two have no solution due to the fact that they develop a false statement when trying to solve.
-3x + 7 = 3x + 7 ----> Subtract 7 from both sides
-3x = 3x ---> Divide by 3
-x = x (UNTRUE STATEMENT)