\(6\times x-4,7\times3=7,9\times47,4-4,7\times3\\ \rightarrow6\times x-14,1=374,46-14,1\\\rightarrow6\times x-14,1=360,36\\ \rightarrow6\times x=360,36+14,1\\ \rightarrow6\times x=374,46\\ \rightarrow x=374,46:6\\ \rightarrow x=62,41\)

\(\left(45,8-y\right)\times2,8=46,06\\ \rightarrow45,8-y=46,06:2,8\\ \rightarrow45,8-y=16,45\\ \rightarrow y=45,8-16,45\\ \rightarrow y=29,35\)

\(x\times9-9=0,9\\ \rightarrow x\times9=0,9+9\\ \rightarrow x\times9=9,9\\ \rightarrow x=9,9:1\\ \rightarrow x=1,1\)

\(a,45413-3456\times5=45413-17280=28133\\ b,222\times3-16777=666-16777=-16111\)

\(\dfrac{-15}{4}-\dfrac{6}{7}+\dfrac{15}{4}\\ =\left(\dfrac{-15}{4}+\dfrac{15}{4}\right)-\dfrac{6}{7}\\ =0-\dfrac{6}{7}\\ =\dfrac{-6}{7}\)