3. A rectangle has length $(3 x+7) \mathrm{cm}$ and width $(2 x-1) \mathrm{cm}$. What is the area of the rectangle? $\mathrm{K}$
A) $(5 x+6) \mathrm{cm}^{2}$
C) $\left(6 x^{2}+11 x-7\right) \mathrm{cm}^{2}$
B) $\left(6 x^{2}-7\right) \mathrm{cm}^{2}$
D) $\left(6 x^{2}-11 x-7\right) \mathrm{cm}^{2}$

Answer

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Answer

The final answer is: $\boxed{6x^2 + 11x - 7}$

Steps

Step 1 ：Find the area by multiplying the length and width: $(3x + 7)(2x - 1)$

Step 2 ：Simplify the expression: $6x^2 + 11x - 7$

Step 3 ：The final answer is: $\boxed{6x^2 + 11x - 7}$