Question

ayúdenme.

resuelve las siguientes inecuaciaciones cuatraticas por formula general.

1. x²+8×15<0
2. x²+5× >14
3. x²-4×-5 >0
4. 2x²-6×+4<0





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Answer 1

1) a = 1; b = 8; c = 15

x = -b ± √b² - 4ac / 2a

x = -8 ± √8² - 4 (1) (15) / 2

x = -8 ± √64 - 60 / 2

x = -8 ± √4 /2

x = -8 ± 2/2

x1 = -8 + 1 = -7

x2 = -8 - 1 = -9

2) a = 1; b = 5; c = -14

x = -b ± √b² - 4ac / 2a

x = -5 ± √5² - 4 (1) (-14) /2

x = -5 ± √25 + 56 /2

x = -5 ± √81/2

x = -5 ± 9/2

x1 = -5 - 9/2 = -19/2

x2 = -5 + 9/2 = -1/2

3) a = 1; b = -4; c = -5

x = -b ± √b² - 4ac / 2a

x = -(-4) ± √(-4)² - 4 (1) (-5) /2

x = 4 ± √16 + 20/2

x = 4 ± √36/2

x = 4 ± 6/2

x1 = 4 + 6/2 = 6

x2 = 4 - 6/2 = 2

4) a = 2; b = -6; c = 4

x = -b ± √b² - 4ac / 2a

x = -(-6) ± √(-6)² - 4 (2) (4) / 4

x = 6 ± √36 - 32/4

x = 6 ± √4/4

x = 6 ± 2/4

x1 = 6 + 2/4 = 13/2

x2 = 6 - 2/4 = 11/2

Espero haberte ayudado. Suerte en los estudios ≧◠◡◠≦.