Verified answer

№1.

[tex]a)(\frac{3}{5} )^{2} *1\frac{2}{3} + 12\frac{2}{9} = \frac{3^2}{5^2} *\frac{1*3+2}{3} + 12\frac{2}{9}= \frac{9}{25} * \frac{5}{3} + 12\frac{2}{9} = \frac{3}{5} + 12+\frac{2}{9}=\\\\=\frac{3*9}{5*9} + \frac{2*5}{5*9} + 12= \frac{27+10}{45} +12=12\frac{37}{45} \\\\\\b)13\frac{4}{5} * 1\frac{7}{23}-(\frac{3}{4} )^{2}= \frac{13*5+4}{5} * 1\frac{23*1+7}{23}-\frac{3^2}{4^2} = \frac{69}{5} *\frac{30}{23} - \frac{9}{16} = 18 -\frac{9}{16} =\\\\=17\frac{7}{16}[/tex]

[tex]c)(11\frac{1}{4} - 8\frac{4}{5})*(\frac{3}{7} )^{2}= (11-8+\frac{5}{4*5} - \frac{4*4}{5*4})*(\frac{3^2}{7^2} )= (3+\frac{5-16}{20})*(\frac{9}{49} )=\\\\ (3-\frac{11}{20} )*(\frac{9}{49})=2\frac{9}{20} * \frac{9}{49} = \frac{2*20+9}{20} *\frac{9}{49} =\frac{49}{20} *\frac{9}{49} =\frac{9}{20}[/tex]