Help me with this I don't know how to do it​

Heather is riding a quadratic function that represents a parabola that touches but does not cross the x-axis at x=-6

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]

Find the value of the variable and the length of each chord for #5 and #6.