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4 votes
Which two numbers add up to ___ and multiply to ___?

1. multiply to -18 add to -17
2. multiply to 36 add to -13
3. multiply to -24 add to -5
4. multiply to -18 add to 7
5. multiply to -36 add to 9
6. multiply to 24 add to 10
7. multiply to 18 add to -9
8. multiply to -36 add to -16

I need help ASAP!

User Tarulia
by
8.1k points

2 Answers

3 votes
It's quite simple :)
1.
-18\ \&\ 1 because
-18+1=-17 AND
(-18)*1=-18
2.
-9\ \&\ -4 because
-9+(-4)=-13 AND
(-9)*(-4)=36
3.
-8\ \&\ 3 because
-8+3=-5 AND
(-8)*3=-24
4.
9\ \&\ -2 because
9+(-2)=7 AND
9*(-2)=-18
5.
12\ \&\ -3 because
12+(-3)=9 AND
12*(-3)=-36
6.
6\ \&\ 4 because
6+4=-10 AND
6*4=24
7.
-6\ \&\ -3 because
-6+(-3)=18 AND
(-6)*(-3)=18
8.
-18\ \&\ 2 because
-18+2=-16 AND
-18*2=-36
User Vaha
by
7.1k points
5 votes
Ok so let's start :)

Ok so first one, numbers need to add to
-17 AND multiply to
-18
First of all you need to check the signs which stands near to those numbers. As you see there is
(-) next to both of them, it means that ONLY one number needs to be with
(-) sign. Why? There is short "instruction" which you need to remember:


(-)*(-)=(+)

(-)*(+)=(-)

If there are to signs next to each other, you can "change" them using "rules" below ;P


(-)+(-)=(+)

(-)+(+)=(-)

So it is possible to add two numbers with
(-) sign next to them which would be equal to
-17 (for example
-5+(-12) but it is impossible to find two numbers which have
(-) sign next to them which will give you also negative number after multiplication :)

Ok it's enough theory for now, it should be much easier now :D

1. So you can multiply
1*-18 which is
-18
Also
-18+1 which is
-17

Rules above should help you to understand what I did below :) In case of any questions you can help me anytime :)

It's quite simple :)

1.
\ \boxed{-18\ AND\ 1}\ because\ -18+1=-17\ AND\ (-18)*1=-18

2.
\ \boxed{-9\ AND\ -4}\ because\ -9+(-4)=-13\ AND\ (-9)*(-4)=36

3.
\ \boxed{-8\ AND\ 3}\ because\ -8+3=-5\ AND\ (-8)*3=-24

4.
\ \boxed{9\ AND\ -2}\ because\ 9+(-2)=7\ AND\ 9*(-2)=-18

5.
\ \boxed{12\ AND\ -3}\ because\ 12+(-3)=9\ AND\ 12*(-3)=-36

6.
\ \boxed{6\ AND\ 4}\ because\ 6+4=-10\ AND\ 6*4=24

7.
\ \boxed{-6\ AND\ -3}\ because\ -6+(-3)=18\ AND\ (-6)*(-3)=18

8.
\ \boxed{-18\ AND\ 2}\ because\ -18+2=-16\ AND\ -18*2=-36
User Peo Bondesson
by
8.5k points