Answer:
x = 6
Explanation:
Using the relationships between the entries in the table, you can find x two different ways.
1.
The numbers down the Total column add to give the one at the bottom:
0.1 + 0.09x = 0.64
0.09x = 0.54 . . . . . . . subtract 0.1
x = 6 . . . . . . . . . . . . divide by 0.9
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2.
The product of the numbers in the first two columns is the number in the third. On the bottom row, this means ...
(2 +x)(0.08) = 0.64
2 +x = 8 . . . . . . . . . . . divide by 0.08
x = 6 . . . . . . . . . . . subtract 2