1. 34.61; tax 7

2. 34.61; sale 15% off

3. 34.61; markup 35%

4. 34.61; tip 20%

I know it's a lot, but I'd be very appreciative to the person who solves this

37.03, 29.42, 46.72, 41.53

Step-by-step explanation:

I'm assuming 1 means tax 7% and 7% in decimals is 7/100 = 0.07. Now the original amount is 34.61 meaning that that is 100%, and 100% in decimals is 100/100 = 1. So easy way of doing these is:

1.) 34.61 + 7% tax = 34.61 (1+.07) = 34.61 (1.07) = 37.03

2.) 34.61 - 15% = 34.61 (1-0.15) = 34.61 (0.85) = 29.42

3.) 34.61 + 35% = 34.61 (1+0.35) = 34.61 (1.35) = 46.72

4.) 34.61 + 20% = 34.61 (1+0.20) = 34.61 (1.20) = 41.53

Note that I did round to the nearest cent since we don't have a coin less than a penny.