Question

9c^2-16/16-24c+9c^2 при c=7/9

Answer 1

/9c^2-16/16-24c+9c^2 при c=7/9
18c²-24c-1=0   18*49/81-24*7/9-1=10 8/9-18 2/3-1=-8 7/9

Answer 2

$\frac{9 c^{2}-16 }{16-24c+9 c^{2} } = \frac{(3c) ^{2}-4 ^{2} }{9 c^{2}-24c+16 }= \frac{(3c-4)(3c+4)}{(3c-4) ^{2} } = \frac{3c+4}{3c-4} \\\\ \frac{3* \frac{7}{9}+4 }{3* \frac{7}{9}-4 } = \frac{2 \frac{1}{3}+4 }{2 \frac{1}{3}-4 }=- \frac{6 \frac{1}{3} }{1 \frac{2}{3} }=- \frac{19*3}{5*3}= -3,8$