Rebecca and brad are married and will file jointly. rebecca earns $300,000 from her single member llc (a law firm). she reports her business as a sole proprietorship. wages paid by the law firm amount to $40,000; the law firm has no significant property. brad is employed as a tax manager by a local cpa firm. their modified taxable income is $375,000 (this is also their taxable income before the deduction for qualified business income). determine their qbi deduction for 2018.