7.
[tex] \dfrac{3^4x^4}{3x^2} = 3^{4 - 1}x^{4 - 2} = 3^3x^2 = 27x^2 [/tex]
10.
[tex] \dfrac{(-2)^5 \times (-3)^4 \times (-5)^3}{(-2)^3 \times (-3) \times (-5)^2} = [/tex]
[tex] = \dfrac{(-2)^5 \times (-3)^4 \times (-5)^3}{(-2)^3 \times (-3)^1 \times (-5)^2} [/tex]
[tex] = (-2)^{5-3} \times (-3)^{4-1} \times (-5)^{3-2} [/tex]
[tex] = (-2)^{2} \times (-3)^{3} \times (-5)^{1} [/tex]
[tex] = (-2) \times (-2) \times (-3) \times -3 \times (-3) \times (-5) [/tex]
[tex] = 4 \times (-27) \times (-5) [/tex]
[tex] = 540 [/tex]
