EXPLANATION:
To get the solution of the simultaneous equation, using the elimination method:
We will have the following steps:
Step 1:
Write the two equations:

Step2: Subtract the two equations:

Step 3: Simplify the expression

Step 4: Substitute x=-2 into the formula:

Therefore, the answer is

Thus,
Option B is correct
Answer:
The sides are as follows: 
Step-by-step explanation:
Starting with the side y, we can use the tan to solve for y:

The side x can be determined using sin:

So, the sides as as follows: 
(you can also verify this result is correct using the Pythagorean theorem)
Answer:
1.75 × 10^3
Step-by-step explanation:
4x10^6=4000000
7x10^9=7000000000
7000000000 divided by 4000000 = 1750
1750=1.75 x 10^3