Your answer is 38-8i because what you do is 1 times 3 and get 3 then 1 times 7i and get 7i then you do -5i times 3 and you get -15i then -5i times 7i and you get -35i2 and the square will cancel out the negative and make it 35 then add that to the 3 and you get 38 then take the -15i +7i and get -8 do your answer is 38-8i