The answer choice is a. y=(-1/2)x
Answer:
^algebra^
#1). a - b=4
a=4 + b .....(equation 1)
#2) a + b=12
(4 + b) + b= 12
4 + b + b=12
4 + 2b=12
2b= 12 - 4
2b =8
b= 8:2
b=4
subtituted b in equation 1
a= 4 + b
a= 4 + 4
a=8
so, the number is 8 and 4
x = 13
subtract x from both sides of the equation
6 = 2x - x - 7
6 = x - 7
add 7 to both sides
6 + 7 = x ⇒ x = 13
As a check
substitute this value into the equation and if both sides are equal then it is the solution
left side = 13 + 6 = 19
right side = (2 × 13) - 7 = 26 - 7 = 19
hence x = 13 is the solution
I am not sure I am right but I think it depends on the size of the X.