Question

qual os valores de x?
cálculos abaixo por favor​

Answer 1

A_

$x^{2}-100=0\\x^{2} =100\\x=\sqrt{100}\\x=10$

B_

$4x^{2} =81\\x^{2} =\frac{81}{4}\\x=\sqrt{\frac{81}{4} } \\x=\frac{9}{2}=4,5$

C_

$(2x-1)*(x+2)=3x-7x^{2} \\2x^{2} +4x-x-2=3x-7x^{2} \\2x^{2} +3x-2=3x-7x^{2} \\-2=-9x^{2} \\x^{2} =\frac{2}{9}\\x=\sqrt{\frac{2}{9}} \\x=\frac{\sqrt{2} }{3}$