Answer: The same amount of book weighed is 14.5.
Step-by-step explanation:
So there is 5 books
9.5 pounds
9.5 + 5 = 14.5
So, Each book weighs about 14.5.
The one that is less because if you use more you wound have any later
Area of a triangle is base × height ÷2
base=8x+4 x=-4/8 x=-1/2
height=3x-4 x=4/3
A=b×h÷2
A=(-1/2×4/3)÷2
A=(-4/6)÷2
A=(-4/6)÷2/1 to divide by fractions flip the second and multiply
A=-4/6×1/2
A=-4/12
A=-1/3
It's obviously none of the above because the true area will have a square root of 3 in it because of the equilateral triangle. They want us to find the approximate area. When I was in school the difference between an approximation and the exact answer was greatly stressed but that seems to be fading of late.
That's a rectangle less an equilateral triangle. The area of an equilateral triangle is
which is easily derived but I won't bother here.

Answer: b