pleaseee helppp

<p>“Prove each of the following using Mathematical induction; show all steps”
pleasee someone help… i have a test on this tommorow and i just need some examples… could you also try to show all steps including the words so i understand how you got there? thakns so much in advance~!</p>

<li><p>-1/2, -1/4, -1/8… -1/2^n = (1/(2^n))-1</p></li>
<li><p>a + (a+d)+(a+2d)+…+[a+(n-1)d] = (n/2)[2a+(n-1)d]</p></li>
<li><p>1^3 + 2^3 + 3^3… + n^3 = (n^2(n+1)^2)/(4)</p></li>
<li><p>show that (3^(4n))-1 is dividislbe by 80 for all positive integral values of n</p></li>
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