20% off means you pay 80% of the price so you multiply by 0.8, and 7% tax means you multiply by 1.07
Resulting cost = 18.99*0.8*1.07 = 16.26
Hope this helps let me know if im wrong!
Just get only one of the placeholder on one side by itself
and do the same thing to both sides so it stays equal
3x+7=5x-21
add 21 to both sides
3x+28=5x
subtract 3x from obht sides
28=2x
sivide both sides by 2
14=x
Answer: 1.8x
Step-by-step explanation: