4(x-1)≤4x simplify on the left
4x - 4 ≤ 4x subtract 4x from both sides
-4 ≤ 0
This answer may be puzzling....but notice.......since this answer is always true.....then, we have an identity and any real number value of x will solve the inequality
Here's the graph of both sides......https://www.desmos.com/calculator/dqi09zvhu3
And notice that the graph of 4x is greater than the graph of 4(x -1) for all real numbers...
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This isn't linear.....let's see if it could be a quadratic in the form of ax^2 + bx + c
We have the following system of equations
a + b + c = 40 (1)
4a + 2b + c = 68 (2)
9a + 3b + c = 116 (3)
Subtracting (1) from (2) gives us 3a + b = 28 (4)
Subtracting (2) from (3) gives us 5a + b = 48 (5)
Subtracting (4) from (5) gives us 2a = 20 ...so.. a = 10
And substituting this into (4) gives us that b = -2
And substituting these two values into (1) we have that c = 32
So our function is
f(x) = 10x^2 - 2x + 32
Here's the graph with a table of values......everything checks out........https://www.desmos.com/calculator/kpamboet7h
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