Use mathematical induction to prove that the statement is true for every positive integer n. 10 + 20 + 30 + . . . + 10n = 5n(n + 1)

Use mathematical induction to prove the statement for all natural numbers n: 1+4+7+10+...+(3n-2)=n/2(3n-1)

Use the mathematical induction to prove that an = 4n+1 + 52n-1 is divisible by 21 for any nЄ N.

Use the principle of mathematical induction to show that the statement is true for all natural numbers. 2² +4² +6² + ... + (2n)² = 2n(n + 1)(2n + 1) 3 Let Pn denote the statement: 22 +4² +6² + ... + (2n)² + Check that P₁ is true: 2² = 4 and 2(C Assume Pk is true: 22 +42 +62 + + (² 2 (2n)² = 2n(n + 1)(2n + 1) 3 2² +4² +6² + ... + (2(k+1))² ))( + ¹)(² 1) (2 1 3 To show that Pk+1 is true, add (2(k + 1))² to both sides of Pk. 2² + 4² + 6² + ... + (2k)² + (2( ))²³ = 2 2 |)²-² = +1 1) 2k(k + 1)(2k + 1) 12( + 3 = Rewrite the right-hand side as a single fraction, and then factor the numerator completely. 3 3 2k(k + 1)(2k + 1) +(2( 3 (k + 1)(2k + 1) Thus P₁ is true. 2 2 :))²