<span> -14x + 11y = 23
+2(7x - 3y = 37)
----------------------
0 + 5y = 97
y = 97/5
y = 19.4
7x - 3(19.4) = 37
7x - 58.2 = 37
7x = 37 + 58.2
7x = 95.2
x = 95.2/7
x = 13.6
Check
-14(13.6) + 11(19.4) = 23
-190.4 + 213.4 = 23
</span>
The answer is 48 feet (D).
Explanation:
To solve this, you must think of the monument and its shadow and Adam and his shadow as a triangle, the person/object being the vertical leg, the shadows being the horizontal leg, and a line connecting them being the hypotenuse. Also, we can assume that these triangles are similar. First, we can set the scale to be 40/5 (the two shadows set a scale because the triangles are similar). Then, we can put x/6 (the actual things are similar, and the scale was established to be building/measurement). Next, we can set the two fractions equal to each other (40/5 = x/6) and solve. We can cross multiply to get 5x = 40 * 6. That goes to 5x = 240. Finally, we can divide by five on each side to get x = 48 feet (D).
I'm going to need more information before I can answer.
