Please help me on this qiestion

pls, I really need help

Erin bought christmas cards for $2 each to send to her family and friends. which variable is the dependent variable?

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

Scenario: a rectangular plot of ground is 5 meters longer than it is wide. its area is 20,000 square meters. question: what equation will you find the dimensions? note: let w represent the width. options: w(w+5)=20,000 w^2=20,000+5 (w(w+5))/2=20,000 w+2(w+5)=20,000