2
a,\(\left(-5\right)^2-\left(5x-3\right)=4^3\)
=>25-5x+3=64
=>25+3-64=5x
=>-36=5x
=>x=-36:5
=>x=-7,2
b,3x-17=x+3
=>3x-x=17+3
=>2x=20
=>x=20:2
=>x=10
c,\(5^x+5^{x+2}=650\)
=>\(5^x+5^x.5^2=650\)
=>\(5^x+5^x.25=650\)
=>\(5^x.\left(1+25\right)=650\)
=>\(5^x.26=650\)
=>\(5^x=650:26\)
=>\(5^x\)=25
=>\(5^x=5^2\)
=>x=2