Answer:
<u><em>C. 2x + 40 = 2868</em></u>
Step-by-step explanation:
In this equation, x is the height of the Empire State Building.
If Sears Tower is 40 feet taller than x, and the sum of their heights is 2868, what we have to do to find x is subtract 40 from 2868, then divide by 2.
This is the same as multiplying x by 2, then adding 40 (just backwards).
Let me demonstrate..
<em>2868 - 40 = 2828</em>
<em>2828 / 2 = 1414</em>
<em>x = 1414</em>
Now let's try the other way..
2x + 40 = 2868
Let x = 1414
<em>2 x 1414 = 2828</em>
<em>2828 + 40 = 2868</em>
And there's your answer again!