Question

Find two numbers whose sum is -2 and whose difference is -6.

Answer 1

Step-by-step explanation:

x+y=-2

x-y=-6

x=-2-y

(-2-y)-y=-6

-2-2y=-6

-2y=-4

y=2

x=-4

Answer 2

Answer:  -4 and 2

Step-by-step explanation:

Let the first number be x and the second number be y , then from the question:

$x + y = -2$ ........................ equation 1

$x - y = -6$ ...................... equation 2

solving the of simultaneous linear equation by substitution method , make x the subject of the formula from equation 1 , that is

$x = -2 - y$ ................. equation 3

substitute $x = -2 - y$ into equation 2 , then we have

$-2 - y - y = -6$

$-2 - 2y = -6$

$-2 + 6 = 2y$

$4 = 2y$

$y = 2$

substitute $y = 2$ into equation 3 to find the value of x , then we have

$x = -2 - 2$

$x = -4$

check:

$x + y = -2$

$-4 + 2 = -2$

Also

$x - y = -6$

-4 - 2 = -6

Therefore: the numbers are -4 and 2