it says find the value of x and then it gives you the triangle and the left side's 19 km and then the bottom is 19 km and then it says solve for z in the perimeter is 57 km and then it's asking what does z equal

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]