Answer:
x = 3.5
y = 8x + 12
Step-by-step explanation:
1) Given the equation
12x = 4(x+2)+20
Expand
12x = 4x+8+20
12x - 4x = 28
8x = 18
x = 28/8
x = 3.5
Hence the value of x is 3.5
2) The standard form of equation in slope intercept form is y = mx+c
m is the slope
c is the y intercept
Get the y-intercept
Substitute m = 8 and (0, 12) into y = mx+c
12 = 8(0)+c
12 = c
c = 12
Get the required equation
Recall that y = mx+c
y = 8x + 12
This gives the required equation