⇒(x+5)^2-x(x-4)=55 b) x(x-7)-3 x+21=0 c) (x-2)^2-x - Dicamon

Question

⇒(x+5)^2-x(x-4)=55 b) x(x-7)-3 x+21=0 c) (x-2)^2-x(x+11)=34 d) (x-3)^2-5 x+15=0

Answer

[     a. (x+5)^2-x(x-4); ⇒(x^2+10 x+25)-x(x-4);                  ⇒ 59; ⇒ x^2+10 x+25-x^2+4 x;           ⇒   14 x+25;              ⇒   14 x;                     x ]   Say

Answer

. [ ( x - 7  ) x ( x - 3  ) - 7 ( x - 3  ] , [ ( x - 3  ) ( x - 7  ) = 0  ] , [ x - 3 = 0  hoac  x - 7 = 0  ] , [ x = 3  hoac  x = 7  ]  . .  . ( x + 5  )^2 - x ( x - 4  ) = 55  (

Giúp mình câu này với!