If you are doing a quadratic, you wil have to do quadratic formula, if you are just doing that, no solution.
Answer:
-2x-7y=-4
Step-by-step explanation:
5x+-7x=-2x
-9y+2y=-7y
1+-5=-4
So -2x-7y=-4
Answer:
She paid 9% of sales tax
Step-by-step explanation:
The sale price of diamond = $375
Let x be percent of sales tax
So, amount of tax = 
So, Amount including tax = 375+3.75x
We are given that Bethany paid $408.75 for a pair of diamond stud earrings.
So, 375+3.75x=408.75
3.75x=408.75-375

x=9
Hence She paid 9% of sales tax