Question

a) 2x+(2x+y)-(3x-y)+9x
b)5x- {5x-[5x-(5x-m)-m]-m} -m
c)- {7x-m-[4m-(n-m-3x)-4x]+n}
d)5xy- {-(2xy+5x)+[3y-(-xy+x+3xy)]}

DEIXA OS CALCULOS.

Answer 1

a) 2x+(2x+y)-(3x-y)+9x

2x + 2x + y - 3x + y + 9x

10x + 2y  , muitos professores aceitam este resultado.

2(5x + y) , todavia, esse é mais chic.

b)5x- {5x-[5x-(5x-m)-m]-m} -m

5x - {5x-[5x-5x+m-m]-m}-m

5x - {5x - 5x + 5x - m + m - m} - m

5x - 5x + 5x -5x +m -m +m -m =

0x + 0m =

0

c) - {7x-m-[4m-(n-m-3x)-4x]+n}

- {7x-m-[4m-n-m-3x-4x]+n}

- { 7x - m - 4m +n +m +3x +4x +n}

-7x +m +4m -n -m -3x -4x -n

-14x +4m -2n

-2(7x -2m +n)

d) 5xy- {-(2xy+5x)+[3y-(-xy+x+3xy)]}

5xy- {-2xy-5x+[3y +xy-x-3xy]}

5xy- {-2xy-5x+3y +xy-x-3xy}

5xy +2xy +5x -3y -xy +x +3xy

19xy +6x -3y