Question

1, thực hiện phép tính ;

a, -5-\((\)-5\()\)-\((\)-4-8\()\)

2, rút gọn ;

a, \((\)-x\(+\)4\()\).\((\)x²\(+\)4x\(+\)16\()\)

b, -3x².\((\)-5x\(+\)4y\()\)\(+\)5xy.\((\)-3x\(+\)2\()\)

c, 4xy.\((\)3x²-5\()\)-3y\((\)4x³-5yx\()\)

Answer 1

1.

a) -5 --5 --4 - 8

Answer 2

Câu 2 :

\(a,\left(-x+4\right)\left(x^2+4x+14\right)\)

=> \(-x^3-4x^2-141x+4x^2+16x+564\)

=> \(-x^3-\left(4x^2-4x^2\right)-\left(141x-16x\right)+564\)

=> \(-x^3-125x+564\)

\(b,3x^2\left(-5x+4y\right)+5xy\left(-3+2\right)\)

=> \(-15x^3+12x^2y+5xy.\left(-1\right)\)

=> \(-15x^3+12x^2y-5xy\)

\(c,4xy\left(3x^2-5\right)-3y\left(4x^3-5yx\right)\)

=> \(12x^3y-20xy-3y\left(4x^3-5xy\right)\)

=> \(12x^3y-20xy-12x+15xy^2\)

=> \(\left(12x^3y-12x^3y\right)-20xy+15xy^2\)

=> \(-20xy+15xy^2\)

#~ Hết~#