Question

Cho A=3x³+2xy³+y²

B=2x²y²+x³-2xy³-5

Tính A+B và A-B

Answer 1

Ta có:

A+B=3x³+2xy³+y²+2x²y²+x³-2xy³-5

A+B=(3+1).x³+(2-2).xy³+y²-2xy³-5

A+B=4x³+y²-2xy³-5

câu khác tương tự

Answer 2

A + B = (3x³ + 2xy³ +y² ) + ( 2x²y² +x³ - 2xy³ - 5 )

= 3x³+2xy³ + y² + 2x²y² + x³ - 2xy³ - 5

= ( 3x³ +x³ ) + ( 2xy³ - 2xy³ ) + y² +2x²y² -5

= 4x³ + y² + 2x²y² -5

A - B = ( 3x³ + 2xy³ + y² ) - ( 2x²y² + x³ - 2xy³ - 5)

= 3x³ + 2xy³ + y² - 2x²y² - x³ + 2xy³ - 5

= ( 3x³ - x³ ) + ( 2xy³ + 2xy³ ) + y² - 2x²y² - 5

= 2x³ + 4xy³ + y² - 2x²y² - 5