What is the reason that when we remove parenthesis the sign of numbers in it change? Eg. x-(90-x) (friends plz solve the above equation too)
Answers
Parentheses around a number could have a variety of meanings. For example,parentheses could indicate any of the following: A negative amount, such as a negative balance in your check register. A credit entry, when a debit entry will not have parentheses.
When you input parentheses for a number and then press “Enter”, the number in the cell will become a negative number immediately. The parentheses will be replaced by the minus sign “-“. To figure out the reason, you may continue reading this article.
Step-by-step explanation:
The rules for removing parentheses
Parentheses will be preceded either by a plus sign +
a + (b −c + d)
or a minus sign −
a − (b −c + d).
When parentheses are preceded by a plus sign +
simply remove them. Nothing changes.
a + (b −c + d) = a + b − c + d.
When parentheses are preceded by a minus sign −
change the sign of every term within the parentheses.
Change + to − and − to + .
a − (b −c + d) = a − b + c − d.
The sign of b within the parentheses is understood to be + . Therefore upon removing the parentheses, that term becomes −b.
−c within the parentheses becomes +c. And +d becomes −d.
In other words: To subtract a sum, subtract each term of the sum.
a − (b −c + d) = a − b + c − d.
Subtract b. Subtract −c—that is add it. And subtract d.
We can justify those two possibilities with examples from arithmetic, because algebra is abstracted—taken from—arithmetic.
For example, here is how we could calculate 256 + 98:
256 + 98 = 256 + 100 − 2
= 356 − 2
= 354.
That is,
256 + (100 − 2) = 256 + 100 − 2.
When we remove those parentheses, nothing changes.
And here is how to calculate 256 − 98:
256 − 98 = 256 − 100 + 2
= 156 + 2
= 158.
That is,
256 − (100 − 2) = 256 − 100 + 2.
When we remove those parentheses, the sign of every term
within the parentheses changes.