\(a,\Rightarrow x\times\left(42+54+4\right)=25400\\ \Rightarrow x\times100=25400\\ \Rightarrow x=254\\ b,\Rightarrow x\times\left(142-41-1\right)=40800\\ \Rightarrow x\times100=40800\\ \Rightarrow x=408\)
a) \(x\)(42+54+4)=15400 b) (142-41-1)\(x\)=10800
\(x\)x100=15400 100x\(x\)=10800
\(x\)=15400:100 \(x\)=10800:100
\(x\)=154 \(x\)=108