Chứng minh rằng: (a - b + c) - (a + c) = - b
BÀI 1: CHỨNG MINH RẰNG:
a) (a - b + c) - (a + c) = - b
b) (a + b) - (b - a) + c = 2a + c
c) - (a + b - c) + (a - b - c) = - 2b
d) a.(b+c)-a.(b+d) = a( c-d)
e) a.(b-c) + a.(d+c) = a. (b+d)
BÀI 2: TÌM X ∈ Z, BIẾT:
a) x. (x + 3) = 0 b) (x - 2).(x + 4) = 0
c) x. (x + 1) . (x - 3) = 0 d) (x^2 + 3) . (x + 1)^2 = 0
a) (a - b + c) - (a + c) = - b
b) (a + b) - (b - a) + c = 2a + c
c) - (a + b - c) + (a - b - c) = - 2b
d) a.(b+c)-a.(b+d) = a( c-d)
e) a.(b-c) + a.(d+c) = a. (b+d)
BÀI 2: TÌM X ∈ Z, BIẾT:
a) x. (x + 3) = 0 b) (x - 2).(x + 4) = 0
c) x. (x + 1) . (x - 3) = 0 d) (x^2 + 3) . (x + 1)^2 = 0