Q72 of 83 Page 45

Observe the following:

1 + 2 – 3 + 4 + 5 – 6 – 7 + 8 – 9 = –5


Change one ‘–’ sign as ‘ + ’ sign to get the sum 9.

We can observe that,


⇒ 1 + 2 – 3 + 4 + 5 – 6 – 7 + 8 – 9


⇒ (1 + 2 – 3) + (4 + 5 – 9) – 6 – 7 + 8


⇒ 0 + 0 + 2 – 7


⇒ 2 – 7


If we change the sign of 7 from ‘–’ to ‘ + ’ it would become,


⇒ 2 + 7


⇒ 9


More from this chapter

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70

Write two distinct integers whose sum is equal to one of the integers.

 71

Using number line, how do you compare

A. two negative integers?


B. two positive integers?


C. one positive and one negative integer?

 73

Arrange the following integers in the ascending order:

–2, 1, 0, –3, + 4, –5

 74

Arrange the following integers in the descending order:

–3, 0, –1, –4, –3, –6