Question

a) 4²x-46=3
b) x²-64=0
c) 3²x +25=4
d) x²-8x =0
e) 6x²+18x =0
f) 3x² =0​

Answer 1

Resposta:

$a)\\ \\ 4x^{2} -46=3\\ \\ 4x^{2} =3+46\\ \\ 4x^{2} =49\\ \\ x^{2} =\frac{49}{4} \\ \\ x=\sqrt{\frac{49}{4} } \\ \\ x=\frac{\sqrt{49} }{\sqrt{4} } \\ \\ x=\frac{7}{2}$

$b)\\ \\ x^{2} -64=0\\ \\ x^{2} =64\\ \\ x=\sqrt{64} \\ \\ x=8$

$c)\\ \\ 3x^{2} +25=4\\ \\ 3x^{2} =4-25\\ \\ 3x^{2} =-21\\ \\ x^{2} =-\frac{21}{3} \\ \\ x^{2} =-7\\ \\ x=\sqrt{-7}$

$d)\\ \\ x^{2} -8x=0\\ \\ x(x-8)=0\\ \\ x'=0\\ \\ x''-8=0\\ \\ x''=8$

$e)\\ \\ 6x^{2} +18x=0\\ \\ 6x(x+3)=0\\ \\ 6x=0\\ \\ x'=0\\ \\ x''+3=0\\ \\ x''=-3$

$f)\\ \\ 3x^{2} =0\\ \\ x^{2} =\frac{0}{3} \\ \\ x^{2} =0\\ \\ x=\sqrt{0} \\ \\ x=0$