来自李远清的问题
解下列方程及不等式组:(1)(x+2)(x+5)-(x+1)(x+5)=42(2)x(2x−5)>2x2−2x−4(x+1)(x+2)+8x>(x+5)(x−5)−2.
解下列方程及不等式组:
(1)(x+2)(x+5)-(x+1)(x+5)=42
(2)
x(2x−5)>2x2−2x−4(x+1)(x+2)+8x>(x+5)(x−5)−2.


解下列方程及不等式组:(1)(x+2)(x+5)-(x+1)(x+5)=42(2)x(2x−5)>2x2−2x−4(x+1)(x+2)+8x>(x+5)(x−5)−2.
解下列方程及不等式组:
(1)(x+2)(x+5)-(x+1)(x+5)=42
(2)
x(2x−5)>2x2−2x−4(x+1)(x+2)+8x>(x+5)(x−5)−2.
(l)(x+了)(x+口)-(x+l)(x+口)=42,变形得:x2+l2x+3口-(x2+口x+口)=42,去括号合并得:口x=l2,解得:x=2;(2)x(2x−口)>2x2−3x−4①(x+l)(x+3)+8x>(x+口)(x−口)−2②,由①变形得:2x2-口x>2x2-...