Question

1) 7/16a2b4, если a=-1/7,b=2

Answer 1

$\displaystyle\bf\\a=-\frac{1}{7} \ \ \ ; \ \ b=2\\\\\\\frac{7}{16} a^{2} b^{4 }=\frac{7}{16} \cdot\Big(-\frac{1}{7} \Big)^{2} \cdot2^{4} =\frac{7}{16} \cdot\frac{1}{49} \cdot16=\frac{7\cdot16}{16\cdot49} =\frac{1}{7}$