Question

[nguyenthihuyentrang]

Bai 1 : Tinh gia tri cac bieu thuc

a) x² + 10x + 26 vs x=45

b) x² - 0,2x + 0,01 vs x= 1,1

Bai 2: Tim x

a) (2x - 5)² - (4x - 1) . (x + 3) = 5

b) (3x + 4 )² - (3x - 1) . (3x + 1)= 2

giup mk, mk tick cho !! camon m.n nhieu@@

Answer 1

[0o0 Nguyễn Đoàn Tuyết Vy 0o0]

nguyenthihuyentrang

( 2x  - 5)²  - ( 4x - 1 ) ( x + 3 ) = 5 

=> ( 2x ) ²   - 2 . 2x. 5 + 5² - 4x² + 12x - 3 - x = 5 

=> 4x²    - 20x + 15 - 4x²  + 11x - 3 = 5 

=> -20x + 11x = 5 + 3 - 15 

=> -9x = -7  =>  x = 7/9 

^^ Học tốt! 

Answer 2

[nguyenthihuyentrang]

M.n giup mk vs ak!! mk se tag k cho m.n, camon ah!