Question

1-Quanto é:

$\times = - b + \sqrt{b {}^{2} } - 4.a.c \\ 2.a$
sendo A=1
B= -7
C=10​

Answer 1

$x = \frac{ - b + \sqrt{ {b}^{2} } - 4ac }{2a}$

$x = \frac{ - ( - 7) + \sqrt{ {( - 7)}^{2} } - 4.1.10 }{2.1}$

$x = \frac{7 + \sqrt{49 - 40} }{2}$

$x = \frac{7 + \sqrt{9} }{2}$

$x = \frac{7 + 3}{2}$

$x = \frac{10}{2}$

x = 5