Using a calculator: cos 70 deg = 0.342. Note: it sounds as tho' you were given several answer options. Where are they?
The easiest terms to check are the first (8x)(2x²) = 16x³ and the last (-5)(-6) = 30. This check eliminates the first choice. The remaining choices differ only in the sign and coefficient of the squared term, so that is the one we need to find.
The squared term will be the sum of the products of factors whose degrees total 2:
(8x)(-5x) + (-5)(2x²) = -40x² -10x² = -50x²
The appropriate choice is
16x³ -50x² -23x +30
(a) q=0
You would simplify the equation.
3+9=12
12+q=12
Then you would eliminate 12 from both sides, by subtracting.
q=0
