Responses (1)
Those are not brackets, they are parentheses. These are brackets: [] and these are curly braces: {}. We use parentheses in algebra and the other goofy symbols in other branches of math. They each have specific meanings.
(x - 4)(x - 7) We do not "remove the brackets". We perform the indicated operations.
x times x = x^2
x times -7 = -7x
-4 times x = -4x
-4 times -7 = 28
-------------------- ADD
x^2 - 11x + 28 <-- ANSWER
A big part of math is pattern recognition. A lot of homework is just fighting with stuff so you will remember the pattern when you see it again. The most common pattern is (x + a) * (x + b) = x^2 + (a + b)x + ab and the special case (x + a) * (x - a) = x^2 - a^2. When you spot the pattern you can just write the answer from memory.