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# n/-2 -1=9 ?????

N/-2-1=9 ????

### 3 Answers by Expert Tutors

Ebenezer O. | Aerospace Engr & Air Traffic Control Grad For General Ed. TutoringAerospace Engr & Air Traffic Control Gra...
4.6 4.6 (13 lesson ratings) (13)
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(n/-2) - 1 = 9

we'd cross the -1 over the equality sign making it +1
so we'd have,

(n/-2) = 9 + 1

which gives;

(n/-2) = 10

open the brackets

n/-2 = 10

to solve for n, we cross multiply both sides remembering that 10 is the same as 10/1
so we'd have;

n * 1 = -2 * 10

giving

n = -20

"we'd cross the -1 over the equality sign making it +1" is more accurately said mathematically as "add 1 to both sides of the equation"
Well not exactly......student are meant to know that when a number crosses over the equality sign, the change from whatever polarity they are (ie positive to negative and negative to positive). That also applies to equation or problems with  < > ≤ and ≥.
Shelly J. | Excellent Maths Tutoring for academic successExcellent Maths Tutoring for academic su...
5.0 5.0 (262 lesson ratings) (262)
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Hi Jeannette,

(n/-2)-1=9
add +1 to both the sides

(n/-2)-1+1=9+1

(n/-2)=10
Multiply (-2) on both the sides to solve for n

(n/-2)(-2)=10(-2)

n=-20
Vivian L. | Microsoft Word/Excel/Outlook, essay composition, math; I LOVE TO TEACHMicrosoft Word/Excel/Outlook, essay comp...
3.0 3.0 (1 lesson ratings) (1)
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Hi Jeannette;
n/-2 -1=9 ?????
I think this is...
(n/-2)-1=9...Please correct me if I am wrong.
Let's multiply both sides by -2...
-2[(n/-2)-1]=-9(2)
A negative number multiplied by a negative number results in a positive number...
n+2=-18
Let's subtract 2 from both sides...
-2+n+2=-18-2
n=-20
Let's check our results...
(n/-2)-1=9
(-20/-2)-1=9
A negative number divided by a negative number results in a positive number...
10-1=9
9=9