a) (x+9)² = [latex](x+9)(x+9) = x^{2} +9x+9x+81 = x^{2} +18x+81[/latex] b) (8+y)² = [latex](8+y)(8+y) = 64+8y+8y+y ^{2} = 64+16y+y ^{2} [/latex] c) (2a+3)² = [latex](2a+3)(2a+3) = 4a+6a+6a+9 = 4a+12a+9[/latex] d)[latex](4x+5y) ^{2} =[/latex] [latex](4x+5y)(4x+5y) = 16x+20xy+20xy+25y = 16 x^{2} +40xy+25y ^{2} [/latex] a) (5-b)² = [latex](5-b)(5-b) = 25-5b-5b+b ^{2} = 25-10b+b ^{2} [/latex] b) (a-4)² = [latex](a-4)(a-4) = a ^{2}-4a-4a+16 = a ^{2}-8a+16[/latex] c) (3a-2b)=[latex](3a-2b)(3a-2b)=9a ^{2} -6ab-6ab+4b ^{2}=9a ^{2}-12ab+4b ^{2} [/latex] d) [latex](7x-1) ^{2} = [/latex] [latex](7x-1)(7x-1) = 49x-7x-7x+1 = 49x-14 x^{2} +1[/latex]
