The 2 smaller triangles are similar. Thus, y is to z as x is to 4. You need 3 such ratios to find the 3 unknowns. Could you try your hand at writing 1 more ratio based upon the illustration?
The critical points are at x = 1 and x = 4 giving you the intervals (-inf, 1), (1, 4) and (4, inf).
By substituting x values in these 3 intervals, you can see that f'(x) is positive in the first and third intervals and negative in the second interval.
This means that f(x) is increasing in the first and third intervals and decreasing in the second interval.
The answer is D.
The unknown number would be 11
738 + 164 = 902
902 / 82 = 11
Ans: 11
The answer is: t<span>he triangles are not similar.</span>
