solve the following:  -2 + 5 = what?is the answer a.13  b.+3  c. -7  d. +7

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cburr's profile pic

cburr | Middle School Teacher | (Level 2) Associate Educator

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Another way to approach this is to picture a number line.  In the middle is 0.  Stretching out to the right is what we are used to, 1,2,3,4,5 etc.  Stretching out to the left is the negative numbers, -1, -2, -3, -4, -5, etc.

 

If you start at -2 on the number line, and add 5 -- that is, move 5 to the right, you end up at +3.

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rleahennis | High School Teacher | (Level 1) Adjunct Educator

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To answer this question, and others like it, re-write the equation and reverse the +s and -s:

In this instance, your equation can be re-written as 5 + -2 , which is the same as 5 - +2 (change the plus sign to a minus and the negative symbol to positive) or

5-2, which I bet you can answer!

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malkaam | Student, Undergraduate | (Level 1) Valedictorian

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solve the following:  -2 + 5 = ?

is the answer a.13  b.+3  c. -7  d. +7

- 2 + 5 = + 3 Answer

Few rules to keep in mind:

  • Different signs are subtracted and the sign of the bigger number is taken.
  • Same signs are added, sign of the bigger number is taken.
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givingiswinning | Student, Grade 10 | (Level 1) Valedictorian

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-2 + 5 = what?

is the answer a.13  b.+3  c. -7  d. +7

the answer is b because -2 + 5 is the same as 5-2 which is 3

udonbutterfly's profile pic

udonbutterfly | Student, College Freshman | (Level 1) Valedictorian

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-2 + 5 = x

This is a very simple. If you want to make it a little easier for you all you have to do it switch the numbers around to something that you're more comfortable seeking which would be:

5 - 2 = x See how simpler it became?

The question is 3 = x

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jess1999 | Student, Grade 9 | (Level 1) Valedictorian

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-2 + 5 =

= +3

You can imagine 5-3 or you can imagine a timeline. For the timeline just imagine that you're on -2 and has to go up 5, so -1 , 0 , 1 , 2 , 3

So your answer to this problem is B. -3

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nisarg | Student, Grade 11 | (Level 1) Valedictorian

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the answer is +3 because think about it this way if you owe the bank 2 dollers your ACCOUNT BALANCE is -2 but if you pay the bank 5 dollers than your bank ballance is $3 because you paid the $2 debt off

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fashionableb1 | Student, Grade 10 | (Level 1) Salutatorian

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-2-5 equals positive 3. When subtracting a negative from a positive, the best and easiest way is just to switch the numbers around. Also you could just plug it in your calculator. 

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zumba96 | Student, Grade 11 | (Level 3) Valedictorian

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This is a simple math problem 

Since -2 + 5 is unknown add them up

You can also rearrange it by 5-2

which in this case the answer is 3 

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jynx1955 | Middle School Teacher | eNotes Newbie

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My students hear this from me:

ADDING and SUBTRACTING "LIKE" SIGNS - Add & Keep Sign.

ADDING "UNLIKE" SIGNS - Subtract the absolute values of both integers and keep the sign of the largest absolute value.

SUBTRACTING "UNLIKE" SIGNS - Turn the problem into an addition problem by reversing the sign of the second integer:

    -3 minus +4     is the same as    -3 plus -4     or -7

    +3  minus -4    is the same as   +3 plus +4    or +7

surajverma8's profile pic

surajverma8 | Student, Undergraduate | (Level 1) Salutatorian

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As I have learned in indian explanation, I want to convey you that:

1. if we add two alzebraic digits then we apply the sign which digit is greater between them. Same way:

"-2+5"

we know that '5' is greater than that of two so we shall apply the '+' sign and because there are two opposite signs so "2" will be deducted from '5' and then:

answer will be "+3".

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neela | High School Teacher | (Level 3) Valedictorian

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Experts have given their considered solutions. Please see whether my solution is of any use to you which is particularly based on group theory we study here in mathematics of around 6th to 9th grade :

To solve -2+5

-2+5= -2+(2+3) , as 5=2+3

-2+(2+3)=(-2+2)+3, by associative law.

=0+3

=3, as 0 is the additive identity, i.e. 0+x=x+0=x, x being any number.

Second method.

-2+5= 5+(-2) , by commutative law, i.e., a+b=b+a for any two numbers a and b are commutative under addition.

5+(-2)= 5-2, as +(-a) or -(+a)=-a, by rule of sign.

5-2= (3+2)-2

(3+2)-2= 3+(2-2), by associative law.

3+(2-2)=3. As 2 and -2 are mutually additive inverse of each other.

Thanks for giving an oppotunity to express.

Hope this helps.

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sdiva1982 | Elementary School Teacher | eNotes Newbie

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Integer Rules:

1. Same sign = add and take the sign

Positive + Positive = add and answer is positive

Negative + Negative= add and answer is negative

2. Different Sign = subtract and take the sign of the larger number.

 

-2+5

Different signs Rule 2 = subtract and take sign of larger number (5)

-2-5 = + 3

 

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