Помогите пожалуйста :3 1. Примеры: 1) 4к^2-1 2)25-16с^ 3)3а^2-6аб+3б^2 4)а^2+10аб+25б^2 5)36-12б+б^2 2. Упростить выражение: 7(2а+5)^2+5(2а-7)^2

[latex]4k^2-1=(2k-1)(2k+1)\\\\25-16c^2=(5-4c)(5+4c)\\\\3a^2-6ab+3b^2=3(a^2-2ab+b^2)=3(a-b)^2\\\\a^2+10ab+25b^2=(a+5b)^2\\\\36-12b+b^2=(6-b)^2\\\\7(2a+5)^2+5(2a-7)^2=7(4a^2+20a+25)+5(4a^2-28a+49)=\\\\=48a^2+420=12(4a^2+35)[/latex]

[latex] 1) 4 k^{2} -1 [/latex] [latex] 4k^{2} =1[/latex] [latex] k^{2} = \frac{1}{4} [/latex] [latex]k= \frac{1}{2} [/latex] 2) [latex]25- 16c^{2} [/latex] [latex] 16c^{2} =25 [/latex] [latex] c^{2} = \frac{25}{16} [/latex] [latex]c= \frac{5}{4} [/latex] 3) [latex] 3a^{2} -6ab+ 3a^{2} [/latex] [latex]3( a^{2} -2ab+ b^{2} )[/latex] [latex]3( a+b)^{2} [/latex] 4)[latex] a^{2} +10ab+ 25b^{2} [/latex] [latex] (a+5b)^{2} [/latex] 5)[latex]36-12b+ b^{2} [/latex] [latex] b^{2} -12b+36[/latex] [latex] (b-6)^{2} [/latex] 7)[latex] (2a+5)^{2}+5 (2a-7)^{2} [/latex] [latex] 4a^{2}+20a+25+5 ( 4a^{2}-28a+49 ) [/latex] [latex] 4a^{2}+20a+25+ 2a^{2}-140a+245 [/latex] [latex] 6a^{2}-120a+270 [/latex] делим всё выражение на 6 [latex] a^{2}-20a+45 [/latex]