Step1. find the how much he buy he buy 45
step2. find the % the % is 4 move to decimal left 4% which is .04
step3. multilply the how much he buy or the % so this is that 45*.04=1.8
step4. what are they said they said tax is like add so we got 1.8+$45=46.8
so the answer is 46.8
look at what is the step and you understand the problem more easy way.
If you put brackets around (2+1), your method of working is:
1) 15-4*(2+1)=3
2) 15-4*3=3
3) 15-12=3
You don't need any more brackets, as the BIDMAS (brackets, Indices, division, multiplication, addition, subtraction) rule does the rest of the job for you.
The answer is therefore: 15-4*(2+1)=3
The grapph one. I’m not sure but the others don’t work so I would go with the graph