Question

Which expression has a value of -18?

A.(6^2+2)-18√81
B.6^2(2-8)√81
C.(6^2+2-8)√81
D.6^2 +2 (8√81)

Answer 1

None

Explanation:

Evaluate each answer option, following the order of operations (PEMDAS).

`\begin{aligned}\textsf{A.} \quad (6^2+2)-18√(81)&=(36+2)-18√(81)\\&=(36+2)-18(9)\\&=38-18(9)\\&=38-162\\&=-124\end{aligned}`

`\begin{aligned}\textsf{B.} \quad 6^2(2-8)√(81)&=36(2-8)√(81)\\&=36(2-8)(9)\\&=36(-6)(9)\\&=(-216)(9)\\&=-1944\end{aligned}`

`\begin{aligned}\textsf{C.} \quad (6^2+2-8)√(81)&=(36+2-8)√(81)\\&=(36+2-8)(9)\\&=(38-8)(9)\\&=(30)(9)\\&=270\end{aligned}`

`\begin{aligned}\textsf{D.} \quad 6^2 +2(8√(81))&=36+2(8√(81))\\&=36+2(8\cdot 9)\\&=36+2(72)\\&=36+144\\&=180\end{aligned}`

Therefore, none of the answers has a value of -18.