Question

[Trang Nguyễn Ngân]

Giup trag vs ak
a) 4(x-3)\(^2\)-(2x-1)(2x+1)=10
b) (x-4)\(^2\)-(x-2)(x+2) = 6
c) 9(x+1)\(^2\)-(3x-2)(3x+2) = 10

 

Answer 1

[Không Tên]

a)   4(x - 3)² - (2x - 1)(2x + 1) = 10

\(\Leftrightarrow\)4(x² - 6x + 9) - (4x² - 1) = 10

\(\Leftrightarrow\)4x² - 24x + 36 - 4x² + 1 - 10 = 0

\(\Leftrightarrow\)-24x + 27 = 0

\(\Leftrightarrow\)-24x = -27

\(\Leftrightarrow\)x = \(\frac{9}{8}\)

Vậy x = 9/8

b)  (x - 4)² - (x - 2)(x + 2) = 6

\(\Leftrightarrow\)x² - 8x + 16 - x² + 4 - 6 = 0

\(\Leftrightarrow\)-8x + 14 = 0

\(\Leftrightarrow\)-8x = -14

\(\Leftrightarrow\)x = \(\frac{7}{4}\)

Vậy x = 7/4

c)  9(x + 1)² - (3x - 2)(3x + 2) = 10

\(\Leftrightarrow\)9(x² + 2x + 1) - 9x² + 4 - 10 = 0

\(\Leftrightarrow\)9x² + 18x + 9 - 9x² + 4 - 10 = 0

\(\Leftrightarrow\)18x + 3 = 0

\(\Leftrightarrow\)18x  =  - 3

\(\Leftrightarrow\)x = \(\frac{-1}{6}\)

Vậy x = -1/6

Answer 2

[katori]

a, ->4(x^2-6x+9) - 4x^2 +1 = 10

-> 4x^2 - 24x + 36 - 4x^2 +1  = 10

-> -24x = -27

-> x = 9/8

b, -> x^2 + 8x -16 -x^2 + 4 = 6

-> 8x = 18

-> x= 9/4

c, -> 9x^2 + 18x + 9 - 9x^2 +4 =10 

-> 18x = -3

-> x = -1/6