Hướng dẫn trả lời:
38.
b) `x^2y + xy^2 + x^2z + xz^2 + y^2z + yz^2 + 3xyz`
`= x^2y + xy^2 + xyz + x^2z + xz^2 + xyz + y^2z + yz^2 + xyz`
`= (x^2y + xy^2 + xyz) + (x^2z + xyz + xz^2) + (xyz + y^2z + yz^2)`
`= xycdot(x + y + z) + xzcdot(x + y + z) + yzcdot(x + y + z)`
`= (xy + xz + yz)cdot(x + y + z)`
Đáp án:
`= (xy + xz + yz)cdot(x + y + z)`