1. when you see 4(x² - 1), then you have to multiply 4 with everything in the bracket. keep in mind that you always have to be cautious of the sign whether it is a positive or a negative.
positive ×/÷ positive = positive
negative ×/÷ negative = positive
positive ×/÷ negative = negative
negative ×/÷ positive = negative
^ you have to remember this.
2. only like terms (same alphabet) can plus or minus each other.
3. simplify by taking out the common factor and placing it outside the bracket.
