3x³y⁵ , x³y⁵ , -7x³y⁵ , 2x³y

-2x³y⁵ + 3x³y⁵ + x³y⁵ + ( -7x³y⁵ ) + 2x³y⁵

= ( -2 + 3 + 1 -7 + 2 ) x³y⁵

= -3x³y⁵

4x³y²

x: (-2,14) = -8/3

x= (-8/3)x (-2,14)

x=428/75

mk cũng đang bị nè

A(x) = 0 \(\Rightarrow\) 2x - 7 + ( x - 14 ) = 0

\(\Rightarrow\) 2x -7 + x -14 = 0

\(\Rightarrow\) ( 2x + x ) - ( 7 + 14 ) = 0

\(\Rightarrow\) 3x - 21 = 0 \(\Rightarrow\) 3x = 21 \(\Rightarrow\) x = 7

a) \(\Rightarrow\) xx = 27 \(\times\) (-3 ) \(\Rightarrow\) x² = -81 ( vô lí )

Vậy không tìm được x

b) \(\Rightarrow\) -xx = -9 \(\times\) 4/49 \(\Rightarrow\) -x² = -36/49

\(\Rightarrow\) -x² = - 6²/7² \(\Rightarrow\) x = 6/7

a) Ta có :

P(x) = 5x³ - 3x + 7 - x = 5x³ - ( 3x + x) +7

= 5x³ - 4x +7

Q(x) = -5x³ + 2x - 3 +2x -2x² -2

= -5x³ -2x² + (2x +2x ) - (3+2 )

= -5x³ -2x² + 4x - 5

b) m(x) = ( 5x³ - 4x +7 ) + ( -5x³ -2x² +4x -5 )

= 5x³ - 4x +7 - 5x³ - 2x² + 4x -5

= ( 5x³ -5x³ ) -2x² + ( 4x -4x ) + (7 - 5 )

= -2x² +2

n(x) = ( 5x³ - 4x + 7 ) - ( -5x³ - 2x² + 4x - 5 )

= 5x³ - 4x + 7 +5x³ +2x² -4x +5

= ( 5x³ + 5x³ ) + 2x² - ( 4x + 4x ) + (7 + 5 )

= 10x³ +2x² - 8x +12

c) m(x) = 0 \(\Rightarrow\) -2x² +2 = 0 \(\Rightarrow\) 2x² = 2

\(\Rightarrow\) x² = 1 \(\Rightarrow\) x = 1 hoặc x = -1