BÀI 83 SGKA) TA CÚ A= X2 – 6X + 11= (X - 3)2 + 2 2VẬY GTNN LÀ 2 TẠI X...

1, - DE THI TOAN HOC KI I
DE THI TOAN HOC KI I
1,0Thay số ta cú M = (7. 5)

2

= 12250,253a 2x

2

y + 4xy

2

– 10 x

3

y

2

=2xy . ( x + 2y – 5x

2

y) 1,03b x

3

– 2x

2

y + xy

2

– 25x = x [( x

2

-2xy + y

2

) – 25]0.5 = x . [ ( x – y)

2

– 5

2

] = x ( x – y – 5). ( x – y + 5)3c x

2

+ 5x +6 = x

2

+ 3x + 2x + 6 = x(x+3) + 2(x+3) = ( x + 2). ( x + 3) 1,04a ( x

2

– 3x ) : x + 2x – 1 = 0

x – 3 +2x - 1 = 0

3x – 3 =0