Corinne solved the equation below:
2 answers:
Answer: No, Corinne is not correct. The explanation is given below.
Step-by-step explanation: The steps of Corinne's solution are as follows:
Step 1 : 5x = 95
Step 2 : 5x − 5 = 95 − 5
Step 3 : x = 90
We are to check whether Corinne is correct or not. If yes, we are to explain.
Corinne's solution is incorrect, because in step 2, Corinne should divide both sides by 5, rather than subtracting 5.
Also, in step 3, she has written (5x - 5) = x, which is incorrect, because (5x - 5) = 5(x - 1).
So, both the steps 2 and 3 are incorrect.
The correct solution is as follows:
Thus, Corinne is incorrect because in place of dividing both sides by 5, she subtracted 5 from both sides.
You might be interested in
Answer: There are 4 male goats.
Step-by-step explanation:
We know that n of the 10 goats are male.
The probability that in a random selection, the selected goat is a male, is equal to the quotient between the number of male goats (n) and the total number of goats (10)
The probability is;
p = n/10
Now the total number of goats is 9, and the number of male goats is n -1
then the probability of selecting a male goat again is:
q = (n-1)/9
The joint probability (the probability that the two selected goats are male) is equal to the product of the individual probabilities, this is
P = p*q = (n/10)*((n-1)/9)
And we know that this probability is equal to 2/15
Then we have:
(n/10)*((n-1)/9) = 2/15
(n*(n-1))/90 = 2/15
n*(n-1) = 90*2/15 = 12
n^2 - n = 12
n^2 - n - 12 = 0
This is a quadratic equation, we can find the solutions if we use Bhaskara's formula:
For an equation:
a*x^2 + b*x + c = 0
The two solutions are given by:
For our case, the solutions will be:
The two solutions are:
n = (1 - 7)/2 = -3 (this solution does not make sense, we can not have a negative number of goats)
The other solution is:
n = (1 + 7)/2 = 4
This solution does make sense, this means that we have 4 male goats.