Let d(x) = 2x - 4
Or
y = 2x - 4
We have replace x = y
x = 2y - 4
Now Isolate "y"
x + 4 = 2y
Pass "2" dividing
(x + 4) / 2 = y
y = x/2 + 2
Or
d(x)^-1 = x/2 + 2
3/6 (r-7) =1 The answer is r=7
Answer:
Train A = 299 tons Train B = 50 tons
Step-by-step explanation:
Train A = x
Train B = y
x+y = 349
x= y +249
Plug in one equation into another
y+249+y= 349
Simplify
2y+249=349
Subtract 249 from both sides
2y=100
Divide both sides by 2
y=50
Plug it into the x equation to solve for x
x+50=349
-50 from both sides
x=299