Question Number 88940 by jagoll last updated on 14/Apr/20
Answered by john santu last updated on 14/Apr/20
![3^3 + (1/4) [3×9+3×7 ] = 27 + 12 = 39 ⇒4^3 + (1/4) [ 4×5+4×3] = 64 + (1/4)×32 = 72 ⇒(A)](Q88942.png)
$$\mathrm{3}^{\mathrm{3}} \:+\:\frac{\mathrm{1}}{\mathrm{4}}\:\left[\mathrm{3}×\mathrm{9}+\mathrm{3}×\mathrm{7}\:\right]\:=\: \\ $$$$\mathrm{27}\:+\:\mathrm{12}\:=\:\mathrm{39}\: \\ $$$$\Rightarrow\mathrm{4}^{\mathrm{3}} \:+\:\frac{\mathrm{1}}{\mathrm{4}}\:\left[\:\mathrm{4}×\mathrm{5}+\mathrm{4}×\mathrm{3}\right]\:=\: \\ $$$$\mathrm{64}\:+\:\frac{\mathrm{1}}{\mathrm{4}}×\mathrm{32}\:=\:\mathrm{72}\:\Rightarrow\left({A}\right) \\ $$
Commented by jagoll last updated on 14/Apr/20
$$\boldsymbol{{thank}}\:\boldsymbol{{you}}\:{S}\mathfrak{ir}\: \\ $$