Prove that the square root of a Mersenne number (

Find the absolute maximum and absolute minimum values of f on the given interval.
${\displaystyle f\left(t\right)=t\sqrt{16-t^2},[-1,4]}$
absolute minimum value
absolute maximum value

Solve the absolute value equation
|2x-3|=7
A) -2,9
B) 9,2
C) -2,5
D) 5,7

Which characteristic of an exponential decay function does not belong with the other three? Explain your reasoning. base of 0.8 decay factor of 0.8 decay rate of 20% 80% decrease

Quadratic formula and isolating f(x)
${\displaystyle f\left(x\right)-\frac{1}{f\left(x\right)}=g\left(x\right)}$

I am taking a beginner linear algebra class and would like a hint on a homework question. I don't need the answer, just a little guidance.
Consider the differential equation:
$\frac{d^{2}x}{d{t}^2}-\frac{dx}{dt}-x=\cos (t).$
We are told that the differential equation has a solution of the form
$x(t)=a\sin (t)+b\cos (t).$
Find $a$ and $b$, and graph the solution.
I don't know how to set up the system to use elimination to solve.

Find x and y, where
7x+4y=5;
and
${\displaystyle -x-\left(\frac{4}{7}\right)y=-\frac{5}{7};}$

Five less than three times an amount x