Answer:
One-half squared is one-fourth.
Step-by-step explanation:
When you divide fractions, you multiply the first term by the reciprocal of the second term. In this example, instead of multiplying 1/2 by 1/4, you now multiply 1/2 by 4. Therefore, one half is equal to 2 fourths.
Y=-x+9 is the correct answer
Answer:
b. Invalid, because the sample may not be representative of the population.
Step-by-step explanation:
A sample of around 10% of the population is needed to be representative.
In this question:
We have a population of 500,000, and a sample of 10,000.
10,000/500,000 = 1/50 = 0.02 = 2% of the population, so not representative, and option b is correct.
Answer:
12
Step-by-step explanation:
12 divided by 1 using long division is 12. As long as a number is divided by 1 the number is the same as the dividends number.
Answer:
Bobby around 131 minutes and Billy around 111 minutes
Step-by-step explanation:
To solve the problem it is important to raise equations regarding what happens.
They tell us that Billy (Bi) and Bobby (Bo) can mow the lawn in 60 minutes. That is to say that what they prune in a minute is giving as follows:
1 / Bo + 1 / Bi = 1/60 (1)
They say Billy could mow the lawn only in 20 minutes less than it would take Bobby, therefore
1 / Bi = 1 / (Bo-20) (2)
Replacing (2) in (1) we have:
1 / Bo + 1 / (Bo-20) = 1/60
Resolving
(Bo - 20 + B0) / (Bo * (Bo-20) = 1/60
120 * Bo - 1200 = Bo ^ 2 - 20Bo
Rearranging:
Bo ^ 2 - 140Bo -1200 = 0
Now applying the general equation
Bo = 130.82 or Bo = 9.17, <em>this last value cannot be because Billy took 20 minutes less and neither can he prune faster than the two together</em>, therefore Bobby only takes around 131 minutes and Billy around 111 minutes
Checking with equation 1:
1/131 +1/111 = ~ 1/60
