Question

Tính giá trị biểu thức 

A=1-25x2-10x 

Answer 1

\(A=1-25x^2-10x\)

\(=-\left(25x^2+10x-1\right)\)

\(=-\left(\left(5x+1\right)^2-2\right)\)

\(=2-\left(5x+1\right)^2\)

Answer 2

A = 1 - 25x^2 - 10x = - ( 25x^2 + 10x - 1 )

= - [ ( 5x + 1 ) ^ 2 - 2 ]

= 2 - ( 5x + 1 ) ^2