Somebody can help me please

Solve the system of equations. y= 2x y= x^2 - 15

If two angles of a triangle have equal measures and the third angle measures 90°, what are the angle measures of the triangle? a. 60°, 60°, 60° b. 45°, 90°, 90° c. 30°, 30°, 90° d. 45°, 45°, 90°

Find a third-degree polynomial equation with rational coefficients that has roots -2 and 6+i