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Points d and e are midpoints of the sides of triangle abc. the perimeter of the triangle is 48 units. what is the value of t? ο ο ο ο 7t +

Need ! give step by step solutions on how to solve number one \frac{9-2\sqrt{3} }{12+\sqrt{3} } number two x+4=\sqrt{13x-20} number three (domain and range) f(x)=2\sqrt[3]{x} +1

With this one. will mark brainliest