What is the sequence of a proportion​

Solve for x and y: 217x + 131y = 913; 131x + 217y = 827

If cos(2x) = tan^2(y), show that cos(2y) = tan^2(x).

Astudent has created the give circuit diagram. it consists of a battery, a resistor, and a light bulb. in one minute, 1.2c of charge flows through the resistor. how much charge flows through the light bulb in one minute?