14x+x方&=49化简, 14x+x方&=49化简 14x+x方&lt
14x+x方&=49化简 14x+x方&=49化简
搞好了 给10分 cxfa-11 14x+x方&=49化简
=x+7&=√98 -√98-7&=49 14x+x^2&=-7+√98 -7√2-7&=X&lt14x+x方&=98 -√98&=49 x^2+14x+49&=98 (x+7)^2&=x&lt
-7根号2 -7 =&lt14x+x^2+49&=98
-7根号2=&x&x+7&=98(x+7)^2&lt
14x+x^2《49(x+7)^2《98-√98《x+7《√98-7-7√2《x《-7+7√2
x^2+14x-49≤0
14x+x方&=49X^2+14X-49&0[-14-根号下(14的平方+4*49)]/2&=X&=[-14+根号下(14的平方+4*49)]/2-7-7根号2&=X&=-7+7根号2}