\(-1,62+\dfrac{2}{5}+x=7\\ \dfrac{2}{5}+x=7-\left(-1,62\right)\\ \: \dfrac{2}{5}+x=8,62\\ x=8,62-\dfrac{2}{5}\\ x=8,22\)

\(A=\left(\dfrac{1}{3}-\dfrac{8}{15}-\dfrac{1}{7}\right)+\left(\dfrac{2}{3}+\dfrac{-7}{15}+1\dfrac{1}{7}\right)\\ A=\dfrac{1}{3}-\dfrac{8}{15}-\dfrac{1}{7}+\dfrac{2}{3}+\dfrac{-7}{15}+1\dfrac{1}{7}\\ A=\dfrac{1}{3}+\dfrac{-8}{15}+\dfrac{-1}{7}+\dfrac{2}{3}+\dfrac{-7}{15}+\dfrac{8}{7}\\ A=\left(\dfrac{1}{3}+\dfrac{2}{3}\right)+\left(\dfrac{-8}{15}+\dfrac{-7}{15}\right)+\left(\dfrac{-1}{7}+\dfrac{8}{7}\right)\\ A=1+\left(-1\right)+1\\ A=0+1\\ A=1\\ \\ B=0,25+\dfrac{3}{5}-\left(\dfrac{1}{8}-\dfrac{2}{5}+1\dfrac{1}{3}\right)\\ B=0, 25 +\dfrac{3}{5}-\dfrac{1}{8}+\dfrac{2}{5}-1\dfrac{1}{3}\\ B=0, 25 +\dfrac{3}{5}+\dfrac{-1}{8}+\dfrac{2}{5}+\dfrac{-4}{3}\\ B=0,25+0,6+\left(-0,125\right)+0,4+\dfrac{-4}{3}\\ B=\dfrac{9}{8}+\dfrac{-4}{3}\\ B=\dfrac{27}{24}+\dfrac{-32}{24}\\ B=\dfrac{-5}{24}\)