multiply the x in the first parentheses by x and 9 in the other parentheses and
multiply the 9 in the first parentheses by x and 9 in the other parentheses and add all together
(x+9)(x+9)
x² + 9x + 9x + 81
x² + 18x +81
multiply the x in the first parentheses by x and -7 in the other parentheses and multiply the -7 in the first parentheses by x and -7 in the other parentheses and add all together
(x-7)(x-7)
x² -7x - 7x +49
x² - 14x +49
(2x-1)² is the same as (2x-1)(2x-1)
multiply the 2x in the first parentheses by 2x and -1 in the other parentheses and multiply the -1 in the first parentheses by 2x and -1 in the other parentheses and add all together
