Answer:
7r³ - 3r² + 20r
Step-by-step explanation:
(9r³ + 5r² + 11r) + (-2r³ + 9r - 8r²)
You can get rid of the parentheses since there is nothing to distribute.
9r³ + 5r² + 11r - 2r³ + 9r - 8r²
Combine like factors.
7r³ - 3r² + 20r
Answer:
If the model is 3 inches tall, the model bookcase should be <em>2 inches</em> wide.
Step-by-step explanation:
When using similar figures, set up a proportion of the model measurements to the actual measurements:

Then cross multiply and solve for x:

If this helped, a brainliest would be greatly appreciated!
Answer:
x=50
Step-by-step explanation:
(x-10)+x+90=180
2x-10+90=180
2x+80=180
2x=100
<u><em>x=50</em></u>
Answer:
4.3
Step-by-step explanation:
Apply trigonometric ratios to find the answer.
Firstly, we need to find the measure of angle theta. In order to do this, we will use triangle BAD.
From angle theta, the trigonometric ratio sine can be used:
sinθ = 
After we find the value, we take the inverse sine of it and the result is approximately 50.7 degrees.
Now, knowing that angles BAD and CAD are the same, we can solve for CD using trigonometric ratio sine.
sin50.7 = opposite/hypotenuse
sin50.7 = CD/5.5
sin50.7 * 5.5 = CD
4.3 ≈ CD