Question 375060
x-0.05x=19  =>  0.95x = 19  =>  x = 20.

0.2a=0.05a+3 =>  0.15a = 3  =>   a = 20.


x/(x+5)=2/3  =>  3x = 2(x+5)  => 3x = 2x +10  =>  x = 10.


3/a+1/2=11/5a  => 3/a + 0.5 = 2.2/a  =>0.8/a = -0.5 => a = -1.6.


x/2=3/(2x+1)  => x(2x+1) = 6  => {{{2x^2 + x-6 =0}}}  =>  (2x - 3)(x + 2) = 0, thus x = 3/2 or x = -2.