Either positive or negative 180°.
A-b=21
5a-2b=18
We can use substitution here. Take the first equation and solve for A. (Picking this one because it's easy)
a = 21+b
Plugin to the second equation:5(21+b)-2b=18
Simplify: 105 + 5b - 2b = 18
Simplify: 105 + 3b = 18
Subtract both sides: 3b = 18-105
Simplify: 3b = -87
Divide: b = -29
Plug back into the first: a=21+b
a = 21 - 29
a = -8
Option D
In this question, we are required to find the total amount he paid to buy the shirt.
It is given that sales tax is 5.5 % over the amount paid.
The cost price of the shirt = $ 24.
The total amount will be = Cost price + 5.5 % of Cost price
Or
Total amount paid = $ 24 × 1.055 (i.e. 100 % + 5.5 %)
Total amount = $ 24 + (5.5 % × $ 24)
Total amount paid = $ 24 + $ 1.32 = $ 25.32
14/32 in simplest form would be 7/16