+0  
 
+1
1695
4
avatar+41 

Two numbers multiply to be -7 and add to be 6. what are the numbers?

 Jul 1, 2019
 #1
avatar
+2

+7 * -1 = -7

+7 +(-1) = +6

 Jul 1, 2019
 #2
avatar+2864 
+3

Notice how -7 is a prime numbers

 

That means -7 has only two factors!

 

They are 1 and -7, OR it can be -1 and 7.

 

--

 

The second phrase you said is that the two numbers add up to 6.

 

So considering the two cases above, which of them add up to 6?

 

You can always make an equation, but the fastest way to this is recognize that 7 is prime.

 Jul 1, 2019
edited by CalculatorUser  Jul 1, 2019
 #3
avatar+118687 
+3

Two numbers multiply to be -7 and add to be 6. what are the numbers?

 

Think about the multiply first.

What are the posititive integer factors of 7  

1 and 7   that is it!

BUT it is -7 so one must be negative and one must be poisitve  so that is

-7 and +1                   or              +7 and -1

 

but they have to add to +6 so which one is right ?

 Jul 1, 2019
 #4
avatar+1713 
+11

THIS PROBLEM IS ALREADY ANSWERED BY HIGHLY QUALIFIED PEOPLE: JUST WANNA GET MY WAY IN(really similar though...)

 

Factors of -7 = ( 7 , -1 ) , ( -7 , 1 )

 

but since the sum is positive,

 

the positive has to be greater. 

 

So the 7 has to be larger than the 1 to make it positive.

 

So it is the first pair, ( 7 , -1 ) is correct.

 

Answer: 7 , -1

 

-\(tommarvoloriddle\)

 Jul 2, 2019
edited by tommarvoloriddle  Jul 2, 2019

2 Online Users