Первых три пожалуйста !!!)

305. [latex] \frac{8ab}{ab-3a^2} [/latex] = [latex] \frac{a(8b)}{a(b-3a)} [/latex] = [latex] \frac{8b}{b-3a} [/latex] 306. [latex] \frac{6ab}{ab-4a^2} [/latex] = [latex] \frac{a(6b)}{a(b-4a)} [/latex] = [latex] \frac{6b}{b-4a} [/latex] 309. [latex] \frac{b^2+10b}{b^2-100} [/latex] = [latex] \frac{b(b+10)}{b^2-10^2} [/latex] = [latex] \frac{b(b+10)}{(b-10)(b+10)} [/latex] = [latex] \frac{b}{b-10} [/latex]