Answer:
mathematics make our brain fast and sharp
Im nor sure which 2 you are reffering to, but I believe 5.1 x 10 to the power of 4 would be 51,000 and the shape with 3 unequal angles is a triangle?
Answer:

Step-by-step explanation:
You can use the work they gave you and continue from there:

First, simplify the numerator:

Finally, simplify the denominator:

Answer: #3 is B. give me a second and i'll try to do #4
Step-by-step explanation:
Answer:
x=4y+1
Step-by-step explanation:
3x−7=12y−4
Step 1: Add 7 to both sides.
3x−7+7=12y−4+7
3x=12y+3
Step 2: Divide both sides by 3.
3x
3
=
12y+3
3
x=4y+1