(14x-13)*(5x+13)=14x*5x+182
70x^2+117x-169=70x^2+182
117x=182+169
117x=351
x=3(14x-13)*(5x+13)=14x*5x+182 5x(14x-13)+13(14x-13)=70x2+182 70x2-65x+182x-169=70x2+182 182x-65x+70x2-70x2-169+169=70x2+182-70x2+169 117x=182+169 117x=351 117x/117=351/117 X=3原长42原宽15原面积630