c) 4y(x – 1) – (1 – x) l) 18x (3 + x) + 3(x + 3)
d) (x – 3) + 3 – x m) 14x y – 21xy + 28x y
e) 7x(x – y) – (y – x) n) 10x(x – y) – 8y(y – x)
Bài toán 3 : Tìm x biết.
a) 4x(x + 1) = 8(x + 1) g) 5x(x – 2000) – x + 2000 = 0
b) x(x – 1) – 2(1 – x) = 0 h) x – 4x = 0
c) 2x(x – 2) – (2 – x) = 0 k) (1 – x) – 1 + x = 0
d) (x – 3) + 3 – x = 0 m) x + 6x = 0
Đáp án:
Giải thích các bước giải:
c) $4y (x – 1) – (1 – x) \\= 4y (x – 1) + (x – 1) \\= (x – 1) (4y + 1) $
Đáp án:
Giải thích các bước giải:
c, 4y(x-1)-(1-x)=4y(x-1)+(x-1)=(x-1)(4y+1)
d, (x-3)+3-x=(x-3)-(x-3)=0
e, 7x(x-y)-(y-x)=7x(x-y)+(x-y)=(x-y)(7x+1)
l, 18x(3+x)+3(x+3)=(x+3)(18x+3)=3(x+3)(6x+1)
m, 14xy-21xy +18xy=11xy
n, 10x(x-y)-8y(y-x)=10x(x-y)+8y(x-y)=(x-y)(10x+8y)=2(x-y)(5x+4y)