Use substitution to solve the systems
y=5x
x+y=-6

x+2y=8
3x-4y=4

Shania's test scores in 8 subjects were 88, 91, 85, 74, 69, 72, 80, and 87. shania found the middle number of her scores. which type of measure did she find?

Prove that quadrilateral is a rhombus.

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]