Please help me find an estimate for b/7.8 = -2.15. What are the steps?

Question

mathstudent55 · Answer

b/7.8 = -2.15
Since b is being divided by 7.8, you need to multiply both sides by 7.8.
Then you will multiply 7.8 by -2.15 to get what b equals.
To estimate 7.8 x (-2.15), first notice you are multplying a positive number by a negative number. What does that mean bout the result? Positive or negative?
Second, 7.8 is close to 8 and 2.15 is close to 2, so estimate it by using 8 and -2.

anonymous · Answer

For step one, wouldn't that give me an answer like: 60.84 = -16.77?
And it would give me a negative number, since 2 opposite signs equals a negative answer.

anonymous · Answer

For the first step, by multiplying it by 7.8, it will cancel out the 7.8 on the left side, leaving you with just b. So it'd be b=-16.77. You can round this to get the estimate. :o)

anonymous · Answer

Ohh, okay, I get it. Thanks guys!