Question

Решить уравнения 1/4х2-1=0; 4/5х2-45=0; х2-16=0 желательно расписать

Answer 1

$frac{1}{4} x^{2} -1=0\\ frac{1}{4} x^{2} =1\\ x^{2} =1: frac{1}{4}=1*4=4\\x _{1} = sqrt{4}=2\\x _{2}=- sqrt{4}=-2\\ frac{4}{5} x^{2} -45=0\\ frac{4}{5} x^{2} =45\\ x^{2} =45: frac{4}{5}=45* frac{5}{4}= frac{225}{4} \\x _{1} = sqrt{ frac{225}{4} }= frac{15}{2}=7,5\\x _{2} = - sqrt{ frac{225}{4} }=- frac{15}{2}=-7,5\\ x^{2}-16=0\\ x^{2} =16\\x _{1} = sqrt{16}=4\\x _{2}=- sqrt{16}=-4$