396,88+0,48*(6,514-0,0000336:0,0024)

0,0000336/0,0024=0,014 6,514-0,14=6,5 6,5*0,48=3,12 396,88+3,12=400

...=396,88+0,48*(6,514-0,014)=396,88+0,48*6,5=396,88+3,12=400 ======================================================