Divide each term by −3-3 and simplify.
Inequality Form:
x≥3
divide total miles by time:
220 / 3.5 = 62.857
rounded to nearest tenth = 62.9 miles per hour
You would use PEMDAS, which means Parenthesis, exponents, multiplication, division, addition" and then subtraction. You would solve the problem in that order
The goal to proving identities is to transform one side into the other. We can only pick one side to transform while the other side stays the same the entire time. The general rule of thumb is to transform the more complicated side (though there may be exceptions to this guideline).
So I'll take the left hand side and try to turn it into 
One way we can do that is through the following steps:

Since we've shown that the left hand side transforms into the right hand side, this verifies the equation is an identity.
Answer:
I think you have to multiple them all around the triangle