Algebra is commonly used in formulas when we do not know at least ... so their 2nd month will be x = 1. Now we know x = 1, we can substitute it into y = 12 + 8x. If 20% = £50.

Algebra is the branch of mathematics that focuses on formulas, and one of its key concepts ... You express a point slope form equation as y – y 1 = m (x – x 1), where m represents the slope ...