3 and -5
Step-by-step explanation:
Begin by creating the two equations that are provided by the information in the question.
x+y=8
and
xy = -15
Now you can solve logically because of the simplicity of the numbers, by listing the factors of 15 and determine which pair will add up to 8
1 and -15
3 and- 5
The Answer is 3 and 5
Or you can solve algebraically by substitution
x+y=8
can be converted to
y=8−x
Now substitute the first equation into the second equation for the y variable.
x(8−x)= 15
Distribute
8x−x^2=15
Set the equation equal to zero.
8x−x^2−15=15−15
Rearrange to put the squared term first.
−x^2+8x−15=0
Factor the trinomial.
-1(x+5)(x-3) = 0#
Set both factors equal to zero.
x+5=0
x=-5
x−3=0
x=3
-5and3 answer......