please someone help!!

1) if matrix X=

|1 1 |

|1 1 |

find a general formula for X^n

2) if matrix Y=

|1 -1 |

|-1 1 |

find a general formula for Y^n

3) Now find a formula for (X+Y)^n

4)Let A=aX

and B=bY

-find general expressions for A^n, and B^n, using an algebraic method to explain how you arrived at your statement.