初一数学书上71页习题2.2的第2、3题的答案,

Question

初一数学书上71页习题2.2的第2、3题的答案,

Answer 1

2.
(1)2(4X-0.5)=8X-1 (2)-3(1-1/6X)=-3+1/2X (3)-x+(2x-2)-(3x+5)=-x+2x-2-3x-5=-2x-7
(4) 3a ²+a²-(2a²-2a)+(3a-a²)= 3a ²+a²-2a²+2a+3a+a²=a²+5a
3.
(1)(5a+4c+7b)+(5c-3b-6a)=5a+4c+7b+5c-3b-6a=-a+9c+4b
(2)(8xy-x²+y²)-(x²-y²+8xy)=8xy-x²+y²-x²+y²-8xy=2y²-2x²
(3)(2x²-1/2+3x)-4(x-x²+1/2)=2x²-1/2+3x-4x+4x²-2=6x²-x-5/2
(4)3x²-[7x-(4x-3)-2x²]=3x²-[7x-4x+3-2x²]=3x²-7x+4x-3+2x²=5x²-3x-3