Question

a) x² - 8x + 15-0 a ) x² - 8x + 15-0​

Answer 1

$d = {b}^{2} - 4ac$

$d = { - 8}^{2} - 4(1)(15)$

$d = 64 - 60$

$d = 4$

$x = \frac{ - b \frac{ + }{ - } \sqrt{d} }{2a}$

$x = \frac{ - ( - 8) \frac{ + }{ - } \sqrt{4} }{2(1)}$

$x = \frac{8 \frac{ + }{ - }2 }{2}$

$x1 = \frac{8 + 2}{2} = \frac{10}{2} = 5$

$x2 = \frac{8 - 2}{2} = \frac{6}{2} = 3$