Question

x square - 7 x + 18 =0 do it by formula method​

Answer 1

Hey mate here is your answer....

$x ^{2} - 7x + 18$

$x ^{2} + 2x - 9x + 18$

$x(x + 2) - 9(x + 2)$

$(x + 2) (x - 9)$

so, x= -2 or 9......ans

Answer 2

${x}^{2} - 7x + 18 = 0$

Here;

$a = 1$

$b = - 7$

$c = 18$

Using quadratic formula;

$\frac{ - b + - \sqrt{ {b}^{2} - 4ac } }{2a} = x \\ = > x = \frac{ - ( - 7) + - \sqrt{ {( - 7)}^{2} - 4 \times 1 \times 18}}{2 \times 1} \\ = > x = \frac{7 + - \sqrt{49 - 72} }{2} \\ = > x = \frac{7 + - \sqrt{ - 23} }{2}$

Since, √-23 is an imaginary number, therefore, there is no real solution of this problem.