Cho 2 đa thức A(x)= 4x ² – 3x ² – 7x =5 B( x)= -4x ³ + 3x ² +4x -11 Tính A(x) + B(x) , A(x) – B(x) 03/09/2021 Bởi Clara Cho 2 đa thức A(x)= 4x ² – 3x ² – 7x =5 B( x)= -4x ³ + 3x ² +4x -11 Tính A(x) + B(x) , A(x) – B(x)
Ta có : `A(x) + B(x) = (4x^2 -3x^2 – 7x + 5) + (-4x^3 + 3x^2 + 4x-11)`` = 4x^2 – 3x^2 – 7x + 5 -4x^3 + 3x^2 + 4x – 11`` = -4x^3 + (4x^2 – 3x^2 + 3x^2) – (7x-4x) + (5-11)`` = -4x^3 + 4x^2 – 3x – 6`Vậy `A(x) + B(x) = -4x^3 + 4x^2 – 3x-6` `A(x) – B(x) = (4x^2 -3x^2 – 7x + 5) – (-4x^3 + 3x^2 + 4x-11)`` = 4x^2 – 3x^2 – 7x + 5 + 4x^3 – 3x^2 – 4x+11`` = 4x^3 + (4x^2 -3x^2 – 3x^2) – (7x + 4x) + (5+11)`` = 4x^3 -2x^2 – 11x + 16`Vậy `A(x) – B(x) = 4x^3 -2x^2 – 11x + 16` Bình luận
A(x)+B(x)=(4x²−3x²−7x+5)+(−4x³+3x²+4x−11) =4x²−3x²−7x+5−4x³+3x²+4x−11 =−4x³+(4x²−3x²+3x²)−(7x−4x)+(5−11) =−4x³+4x²−3x−6 Vậy A(x)+B(x) =(4x²−3x²−7x+5)−(−4x³+3x²+4x−11) =4x²−3×2−7x+5+4x³−3x²−4x+11 =4x³+(4x²−3x²−3x²)−(7x+4x)+(5+11) =4x³−2x²−11x+16 Vậy A(x)−B(x) mk gui bn Bình luận
Ta có :
`A(x) + B(x) = (4x^2 -3x^2 – 7x + 5) + (-4x^3 + 3x^2 + 4x-11)`
` = 4x^2 – 3x^2 – 7x + 5 -4x^3 + 3x^2 + 4x – 11`
` = -4x^3 + (4x^2 – 3x^2 + 3x^2) – (7x-4x) + (5-11)`
` = -4x^3 + 4x^2 – 3x – 6`
Vậy `A(x) + B(x) = -4x^3 + 4x^2 – 3x-6`
`A(x) – B(x) = (4x^2 -3x^2 – 7x + 5) – (-4x^3 + 3x^2 + 4x-11)`
` = 4x^2 – 3x^2 – 7x + 5 + 4x^3 – 3x^2 – 4x+11`
` = 4x^3 + (4x^2 -3x^2 – 3x^2) – (7x + 4x) + (5+11)`
` = 4x^3 -2x^2 – 11x + 16`
Vậy `A(x) – B(x) = 4x^3 -2x^2 – 11x + 16`
A(x)+B(x)=(4x²−3x²−7x+5)+(−4x³+3x²+4x−11)
=4x²−3x²−7x+5−4x³+3x²+4x−11
=−4x³+(4x²−3x²+3x²)−(7x−4x)+(5−11)
=−4x³+4x²−3x−6
Vậy A(x)+B(x)
=(4x²−3x²−7x+5)−(−4x³+3x²+4x−11)
=4x²−3×2−7x+5+4x³−3x²−4x+11
=4x³+(4x²−3x²−3x²)−(7x+4x)+(5+11)
=4x³−2x²−11x+16
Vậy A(x)−B(x)
mk gui bn