Can you please help me with this question

In trapezoid efgh, m∠hef=(4x2+16)∘ and m∠gfe=(5x2+12)∘. find the value of x so that efgh is isosceles. i'm desperate.

Consider the system: y = 3x + 5 y = ax + b what values for a and b make the system inconsistent? what values for a and b make the system consistent and dependent? explain

You have $600,000 saved for retirement. your account earns 5.5% interest. how much, to the nearest dollar, will you be able to pull out each month, if you want to be able to take withdrawals for 20 years?