Answer:
Step-by-step explanation:
to solve this system of equation using substitution method
A) y=2x and y=x-4
let
y=2x................................... equation 1
y=x-4.................................. equation2
substitute equation 1 into equation 2
y=x-4.................................. equation2
2x = x - 4
collect the like terms
2x - x = -4
x = -4
put x = -4 into equation 1
y=2x................................... equation 1
y= 2(-4)
y = -8
therefore x = -4 and y = -8.
question B
let
y=x+6..................................... equation1
y=3x ..................................... equation2
substitute equation 2 into equation 1
y=x+6..................................... equation1
x + 6 = 3x
6 = 3x -x
6 = 2x
divide both sides bu the coefficient of x which is 2
6/2 = 2x/2
x = 3
put x = 3 into equation 2
y=3x ..................................... equation2
y = 3(3)
y = 9
therefore x and y is 3 and 9 respectively
QUESTION C
let
y= -3x ..................................... equation 1
y= x-4 ...................................... equation 2
substitute for equation 1 in equation 2
y= x-4 ...................................... equation 2
-3x = x- 4
collect the like terms
-3x - x = -4
-4x = -4
divide both sides by -4
-4x/-4 = -4/-4
x = 1
put the value of x = 1 into equation 1
y= -3x ..................................... equation 1
y = -3(1)
y = -3
therefore the value of x and y i this system of equation is 1 and -3 respectively.
QUESTION D
let
y=x/3 .............................................. equation 1
y=x+4 ............................................... equation 2
substitute equation 1 into equation 2
y=x+4 ............................................... equation 2
x/3 = x + 4
multiply through by 3
x = 3x + 12
collec the like terms
x - 3x = 12
-2x = 12
divide both sides by -2
-2x/-2 = 12/-2
x = -6
put the value of x = -6 into equation 1
y=x/3 .............................................. equation 1
y = -6/3
y = -2
therefore the value of x and y is -6 and -2 respectively.
