You need to add the two quadratics together...
x^2+11x-6+6x^2-3x+9
7x^2+8x+3
The doorstop is a triangular prism. volume of the triangular prism is the area of the base times the height
area of the base: 1/2 * 10*6=30cm²
height: 2.5cm
Volume: 30cm²*2.5cm=75cm³
weight: 75cm³*8.6g/cm³=645 grams
Answer:
c
Step-by-step explanation:
