10.5X -( 1/4) = (7/2) (three and a half equals seven-thirds)

10.5X = (7/2) + ( 1/4)

10，5X = ( 14/4) + ( 1/4)

10.5X = 15/4

X = (15/4) ÷ (42/4) (ten point five equals forty-two).

X = 14/5

PS: This involves mathematical knowledge points such as changing fractions into false fractions, changing decimals into false fractions, and common fractions between different denominators. You must be careful when doing this kind of problem.