Question

Rút gọn

( x -3 ) . ( x -5 ) -( x - 4)^2

Answer 1

\(\left(x-3\right)\left(x-5\right)-\left(x-4\right)^2\)

\(=x^2-5x-3x+15-\left(x^2-8x+16\right)\)

\(=x^2-5x-3x+15-x^2+8x-16\)

\(=x^2-x^2-8x+8x+15-16=-1\)

Answer 2

(x - 3)(x - 5) - (x - 4)²

= x² - 5x - 3x + 15 - x² + 8x - 16

= (x² - x²) + (-5x - 3x + 8x) + (15 - 16)

= -1

Answer 3

( x -3 ) . ( x -5 ) -( x - 4)^2=x^2 -5x-3x+15-(x^2 -8x+16) x^2-5x-3x+15-x^2+8x-16=-1  

Answer 4

\(\left(x-3\right).\left(x-5\right)-\left(x-4\right)^2\)

\(=x-3.x-5=x^2-5x-3x+15\)

\(=x^2-8x+15\)

\(=\left(x-4\right)^2=\left(x-4\right).\left(x-4\right)\)

\(=x^2-4x-4x+16=x^2-8x+16\)

\(=\left(x^2-8x+15\right)-\left(x^2-8x+16\right)\)

\(=x^2+8x-16=-1\)

Vậy giá trị cần tìm là: \(-1\)

Answer 5

(x−3)(x−5)−(x−4)2

=�2−5�−3�+15−(�2−8�+16)=x2−5x−3x+15−(x2−8x+16)

=�2−5�−3�+15−�2+8�−16=x2−5x−3x+15−x2+8x−16

=�2−�2−8�+8�+15−16=−1=x2−x2−8x+8x+15−16=−1