a, \(420+65:4=\left(x+175\right):5+30\)
\(\Rightarrow\left(x+175\right):5+30=420+16,25\)
\(\Rightarrow\left(x+175\right):5=420+16,25-30=406,25\)
\(\Rightarrow x+175=2031,25\)
\(\Rightarrow x=1856,25\)
b, \(\left(32.15\right):2=\left(x+70\right):14-40\)
\(\Rightarrow\left(x+70\right):14-40=480:2\)
\(\Rightarrow\left(x+70\right):14=240+40=280\)
\(\Rightarrow x+70=3920\Rightarrow x=3850\)
c, \(x-4867=\left(175.2050.70\right):25+23\)
\(\Rightarrow x=39462500:25+23+4867\)
\(\Rightarrow x=1578500+23+4867=1583390\)
Chúc bạn học tốt!!!