What is the factored form of these expressions?
1. d2 + 18d + 81
a. (d + 9)(d – 9)
b. (d + 9)2
c. (d – 81)(d – 1)
d. (d – 9)2

2. d2 + 22d + 121
a. (d + 11)2
b. (d – 11)2
c. (d – 11)(d + 11)
d. (d – 121)(d – 1)

3. r2 – 49
a. (r – 7)(r + 7)
b. (r + 7)(r + 7)
c. (r – 7)(r – 7)
d.(r – 7)(r + 9)

Organisms that live in the alpine and taiga biomes have developed unique adaptations that aid in their survival. the douglas-fir is a conifer tree that grows in the taiga biome. it has an average height of about 70 feet, and its wood is an important source of lumber.

What are the soultion(s) to the quadratic equation 40- x^2=0

During your cycling trip, you and your friends often stayed in hostels. the prices of these are listed below. hostel standard room (price per night) with breakfast (price per night) super sleep hostels £22.45 £28.65 normandy nights £18.55 £25 zzzola hostels £24.50 £30.99 belgian beds £11.20 £18.55 night-time rest days ? £33 what is the range in cost for a single night, including both standard room prices and with breakfast prices?