You answer 95% of the questions correct in a 40 question test how much did u get wrong

Solve each quadratic equation by factoring and using the zero product property. n^2 - 49 = 0

Can someone plz me understand how to do these. plz, show work. in exercises 1-4, rewrite the expression in rational exponent form.[tex]\sqrt[4]{625} \sqrt[3]{512} (\sqrt[5]{4} )³ (\sqrt[4]{15} )^{7}\\ (\sqrt[3]{27} )^{2}[/tex]

Tanyss's house has 25 windows. her brother has washed 22 of the windows. what percent of the windows has her brother washed?