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
Answer:
Refer to the picture above
I think that you assumed that:
2k - 1 = k + 2
However we can't do this, because a square has 4 sides whilst a triangle only has 3 sides.
This means that we can say
4(2k - 1) = 3(k + 2)
We multiply by 4 due to 4 sides of the square, and by 3 due to the 4 sides of the triangle.
Lets expand the brackets, and solve it:
4(2k - 1) = 3(k + 2)
8k -4 = 3k + 6
5k -4 = 6 ( subtract both sides by 3x to collect the x values)
5k = 10 (add both sides by 4 to get the x's alone)
k = 2 (divide both sides by 5 to get what just x is)
So k = 2 units
The answer would be 9.4 miles.
