Answer:
It's the law of cosines
Step-by-step explanation:
law of cosines states that 
so we know that a = 7, b = 4, and alpha would be 135 degrees, so just plugging it in gets us 49+16-2*7*4*(-0.707) = 65 + 39.59 = 104.59
Answer:
-38 - 12x < 200
Step-by-step explanation:
Given,
The original elevation = -38 feet,
Also, the explorer starts moving at a rate of negative 12 feet per minute.
So, the distance covered by explorer after x minutes = -12x feet,
Thus, the final elevation = original elevation + distance covered by explorer
= -38 - 12x
According to the question,
final elevation < -200 feet
⇒ -38 - 12x < 200
Which is the required inequality.
-x + 4 = 2x + 1
add x to both sides
4 = 3x + 1
subtract 1 from both sides
3 = 3x
dived 3 from both sides
1 = x
Use multiplication:

This question is basically the same as the other question of yours that I answered, so the explanation is very similar:
You can imagine the possibilities as leaves on a tree. Your tree has 2 large branches to represent the two possible sizes. Each of those branch off into 8 smaller branches, each representing a crust flavor. Each one of the smaller branches has 8 leaves to represent a different topping. Each leaf is a combination of a size, a crust flavor, and a topping, so it represents a complete pizza. Your job is to calculate the number of leaves.
20 thousands would be 200 hundreds