First step cross multiplying.
6.2/2x+1=213/4
(6.2)*(4)=213*(2x+1)
24.8=426x+213
Second Step flip with the equation.
426x+213=24.8
Third Step Subtract 213 from both sides.
426x+213−213=24.8−213
426x=−188.2
Fourth Step Divide both sides of 426.
426x/426 = -188.2/426
Answer is x= -0.441784