kurangkanlah a. 5x - 4y dari 3x +y b. 4x +1 dari 2 (x-3) c. 2 (a-b+c)dari a-b-c d. 3 (x2-2x-1)dari 2 (-x2 -x+4)

a. 3x + y - (5x - 4y)
= 3x + y - 5x + 4y
= - 2x + 5y

b. 2(x - 3) - (4x +1)
= 2x - 6 - (4x + 1)
= 2x - 6 - 4x - 1
= -2x -7

c. a - b - c - (2(a - b + c))
= a - b - c - ( 2a - 2b + 2c)
= a - b - c - 2a + 2b - 2c
= a + b - 3c

d. 2(-x^2 - x + 4) - (3(x^2 - 2x +1))
= - 2x^2 - 2x + 8 - ( 3x^2 - 6x + 3)
= - 2x^2 - 2x + 8 - 3x^2 + 6x - 3
= -5x^2 + 4x + 5