Question

what are the root of quadratic equation x² = 81 ?​

Answer 1

Answer:

${x}^{2} - 0x - 81 = 0$

Product= -81

Sum=0

Numbers=9,-9

${x}^{2} - 9x + 9x - 81 = 0$

$( {x}^{2} - 9x) + (9x - 81) = 0$

$x( x - 9) + 9(x - 9) = 0$

$(x + 9)(x - 9) = 0$

$x + 9 = 0 \: \: or \: \: x - 9 = 0$

$x = - 9,9$

So the roots of the given solution

x=-9,9