Question

What two numbers have a sum of -5 and a product of 6?

Answer 1

let "a" be the value of the first number
let "b" be the value of the 2nd number

sum means add
product means multiply

the sum of 2 numbers is -5
a+b=-5
the product of 2 numbers is 6
a*b=6

solve by using substitution

Answer 2

yeah i got that but i cant figure out how to solve it

Answer 3

lets say i solve for a for the product of 2 numbers

a*b=6

solving for a
a=6/b

now since i know "a", i can substitute that into the other equation

Answer 4

yeap so 6/b+b=-5

Answer 5

What two numbers can you think of at the top of your head that can be used to equal 6 & 5? :)

Answer 6

I'd rather them learn how to solve it than just be given the answer and not know how to solve it..

Answer 7

well yea, you could just guess and check, but there's still a process

and dont give out answers, you know better than that

Answer 8

thanks for the answer, @completeidiot was just trying to explain how to solve it and show working out, no need for the "common sense" thanks

Answer 9

yes a quicker method would just be to determine all the multiples of -6, then just plug in the values to see which works

Answer 10

okay thankyou very much :)

Answer 11

im just gonna go through all the steps

a=6/b
a+b=-5

6/b+b=-5

6+b^2=-5b

b^2+5b+6=0

(b+2)(b+3)=0

b= -2, b=-3