Prove the following by induction. in each case, n is apositive integer.
2^n ≤ 2^n+1 - 2^n-1 -1.

What is the explicit formula for this sequence? -7, -4, -1, 2, a.) an = 8 + (b - 1)3 b.) an = -7 + (n - 1)3 c.) an = 3 + (n -1) (-7) d.) an = -7 + (n - )

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

Math question.. plz me .. best answer all