Tax liability Determine the taxable amount of Social Security benefits for the following situations. If required, round your answers to the nearest dollar. If an amount is zero, enter "0". a. Erwin and Eleanor are married and file a joint tax return. They have adjusted gross income of $40,200, no tax-exempt interest, and $14,070 of Social Security benefits.

a) As a result, ???? of the Social Security benefits are taxable.

Please could you tell me what I am doing wrong:

(50%*12,000)+(85%*(14,070-12,000)=7759.50 but the professor said that is wrong I should get in 8,750. How?