3x +7y=10 and I’m solving for y and I got multiple awnsers
1 answer:
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Answer: 44 hours.
Step-by-step explanation:
Marisol is being paid $792.
We know that the job took her 8 hours more than she expected, so if we define T as the time she expected, this job took her:
T + 8 hours.
The amount of money per hour that she expected is calculated as:
$792/T = X
And for those 8 extra hours, she won $4 less per hour, then we have:
$792/(T + 8hs) = X - $4
Then we have a system of equations:
$792/T = X
$792/(T + 8hs) = X - $4
To solve this, we can notice that in the first equation X is isolated, then we could replace that in the second equation to get:
$792/(T + 8hs) = $792/T - $4
Now we can solve this for T.
$792 = ($792/T - $4)*(T + 8hs) = $792 + $792*(8hs/T) - $4*T + $32*hs
0 = $792*(8hs/T) - $4*T + $32*hs
Let´s multiply this both sides by T
0*T = ($792*(8hs/T) - $4*T + $32*hs)*T
0 = $792*8hs - $4*T^2 +$32*T*hs
This is a quadratic equation, where i will write this witout units so it is easier to read and follow:
0 = -4*T^2 + 32*T + 792*8
The solutions cab be found by using the Bhaskara´s formula, these are:
Then the solutions are:
T = (-32 + 320)/-8 = -36 hours (This is a negative time, and it does not really have a meaning in this problem, so we can discard this option)
The other solution is:
T = (-32 - 320)/-8 = 44 hours.
Then we can conclude that she expected the job would take 44 hours in total.
Answer:
a) Dice and spinner are different objects, with no relation between themselves, and thus her dice rolls and spinning outcomes are independent.
b) probability of her rolling a 4 and spinning an 8.
c) probability of her rolling an even number and spinning a number less than 3.
Step-by-step explanation:
A probability is the number of desired outcomes divided by the number of total outcomes.
A) Are her dice rolls and spinning outcomes independent or dependent?
Dice and spinner are different objects, with no relation between themselves, and thus her dice rolls and spinning outcomes are independent.
B) What is the probability of her rolling a 4 and spinning an 8?
Since the events are independent, we find each separate probability and multiply them.
Probability of rolling a 4:
One side out of 6 on the dice. So
Probability of spinning an 8:
One side out of 8 on the spinner. So
Probability of rolling a 4 and spinning an 8:
probability of her rolling a 4 and spinning an 8.
C) What is the probability of her rolling an even number and spinning a number less than 3?
Since the events are independent, we find each separate probability and multiply them.
Probability of rolling an even number:
2, 4 or 6(3 sides out of 6). So
Probability of spinning a number less than 3:
Two numbers(1 or 2) out of 8 on the spinner. So
Probability of rolling an even number and spinning a number less than 3:
probability of her rolling an even number and spinning a number less than 3.