Help me wit math questions pls

Suppose that x and y are both differentiable functions of t and are related by the given equation. use implicit differentiation with respect to t to determine startfraction dy over dt endfraction in terms of x, y, and startfraction dx over dt endfraction .

Which steps could be part of the process in algebraically solving the system of equations, y+5x=x^2+10 and y=4x-10

Sum of the interior angles of a pentagon