The answer is 80, 2x+3x+4x=180, so x=20. 20*4=80.
50 inches 4/5*x=40
x=40/(4/5)
x=40*5/4=200/4=50 x=50 inches
The equation to show the depreciation at the end of x years is

Data;
- cost of machine = 1500
- annual depreciation value = x
<h3>Linear Equation</h3>
This is an equation written to represent a word problem into mathematical statement and this is easier to solve.
To write a linear depreciation model for this machine would be
For number of years, the cost of the machine would become

This is properly written as

where x represents the number of years.
For example, after 5 years, the value of the machine would become

The value of the machine would be $500 at the end of the fifth year.
From the above, the equation to show the depreciation at the end of x years is f(x) = 1500 - 200x
Learn more on linear equations here;
brainly.com/question/4074386
16y-4, i got this by you need to multiply the 4y and the other 4y. 2 times -2 = -4.