Okay so -6 + Y = 0
Y = his total score on the first day
so you can do 0- (-6)= Y
answer Y= 6
first day he got a score if 6
X^4 - x^2 + 9 - (x^3 + 3x^2 + 12) =
x^4 - x^3 - 4x^2 - 3
Answer:
<h2>By angle sum property:</h2>
BAC+ABC+BCA=180°
90°+45°+x=180°
135°+x=180°
x=45°=BCA
<h2>since BCA=ABC=<u> </u>45° each </h2><h2>therefore,</h2>

<h2><em><u>Hope </u></em><em><u>it </u></em><em><u>helps</u></em><em><u> you</u></em><em><u><</u></em><em><u>3</u></em></h2>