Fill in the number according to the rule: 1, 5, 9, 13, 17___ ， ___ ，… The nth number is___ ． | Math enthusiast | Mathematical art

Fill in the number according to the rule: 1, 5, 9, 13, 17_ ， _ ，… The nth number is___ ．

∵1=4-35=4×2-39=4×3-3… The nth term is 4n-3

Fill in the number according to the rule: 1, - 5,9, - 13,17, (), (), the nth number ()

-21; 25; - 1 times (1 + 4) (n is not equal to 1)

Solve the inequality 1. | 2x + 4 | greater than 3 2. The square of X is less than 16

1. | 2x + 4 | greater than 3 (2x + 4) ^ 2 > 9 4x ^ 2 + 16x + 7 > 0 (2x + 7) (2x + 1) > 0, the solution is x > - 1 / 2, X

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