Sorry I am a little late...
a = -2
b = -9
Here is how to solve the problem.
First thing I did was multiply the first equation by -2 so that we can eliminate the the b. After you multiply it by -2, your new equation is -16a + 8b = -40.
You leave the second equation alone and all you do is combine like terms. So -16a+5a is -11. And you eliminate the b. Then you're going to do -40+62 which is 22. So it's -11a=22 and then you have to solve for a. What I did was I multiplied the whole thing by minus to turn the a positive. So then it's 11a=-22. Pretty easy, the final step is to simplify. -22/11 is -2. ;D
So there you have your first answer.
a = -2
Now we're going to use the first answer to help us find b.
For the second equation, all you're going to do is plug in that a.
5 (-2)-8b=62
-10 - 8b = 62
Now we move the -10 to the other side...
-8b = 62 + 10
-8b = 72
Multiply the whole thing by negative once again to turn the b positive.
Now we have 8b = -72
The final step is to simplify. -72/11 = -9
b = -9
Hope this makes sense! Also I had the same question on my test and I got it right. :)
Answer:
231/8 simplified is 28 7/8
Step-by-step explanation:
first you have to convert all mixed fractions into improper fractions so 8 1/4 will become 33/4 and 3 1/2 will become 7/2 and then just multiply and you get 231/8 which simplified is 28 7/8
Answer:
22.60% probability that exactly 3 people are repeat offenders
Step-by-step explanation:
For each driver arrested selected, there are only two possible outcomes. Either they are repeat offenders, or they are not. The probability of an arrested driver being a repeat offender is independent from other arrested drivers. So we use the binomial probability distribution to solve this problem.
Binomial probability distribution
The binomial probability is the probability of exactly x successes on n repeated trials, and X can only have two outcomes.

In which
is the number of different combinations of x objects from a set of n elements, given by the following formula.

And p is the probability of X happening.
In Illinois, 9% of all drivers arrested for DUI (Driving Under the Influence) are repeat offenders;
This means that 
Suppose 28 people arrested for DUI in Illinois are selected at random.
This means that 
a) What is the probability that exactly 3 people are repeat offenders
This is 


22.60% probability that exactly 3 people are repeat offenders