Question 1207907
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Which of the expressions is not equal to the other three?
A. 7[a +2]
B. 20 + 8a -6 -a
C.17 +3[a -1] + 4a
D. 2a + 5[a -1] + 8
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One way to solve this problem is to simplify each expression to its simplest form
and compare them.


I will use another way. I will quickly calculate in my head the value of each expression for a = 0.


(A)  gives the value of 14.

(B)  gives the value of 14.

(C)  gives the value of 14.

(D)  gives the value of  3.


So, I conclude that expression (D) is not equal to (is different from) other three.
</pre>

Solved.