Answer: The corrected statement is A - B = -B + A.
Step-by-step explanation: Given that the subtraction of a matrix B may be considered as the addition of the matrix (-1)B.
We are given to check whether the commutative law of addition permit us to state that A - B = B - A.
If not, We are to correct the statement.
If the subtraction A - B is considered a the addition A + (-B), then the commutative law should be stated as follows :
A + (-B) = (-B) + A.
That is, A - B = -B + A.
Thus, the corrected statement is A - B = -B + A, not B - A.
20L = 20,000mL. 20,000 / (22+3) people = 800mL/person
Answer:
495 combinations of 4 students can be selected.
Step-by-step explanation:
The order of the students in the sample is not important. So we use the combinations formula to solve this question.
Combinations formula:
is the number of different combinations of x objects from a set of n elements, given by the following formula.
How many combination of random samples of 4 students can be selected?
4 from a set of 12. So
495 combinations of 4 students can be selected.
