1) 2x+xy-y = -2
[tex]2x + xy - y \\ 2(2) - 2(2) - 2 \\ 4 - 4 - 2 \\ - 2[/tex]
2) 3x^3+2x^2+x+1 = -1
[tex]3 {x}^{3} + 2 {x}^{2} + x + 1 \\ 3( - 1)^{3} + 2( - 1)^{2} + ( - 1) + 1 \\ - 3 + 2 - 1 + 1 \\ - 2 + 1 \\ - 1[/tex]
3)(x+y)(x+y) =1225
[tex](x + y)(x + y) \\ (15 + 20)(15 + 20) \\ (35)(35) \\ 1225[/tex]
4) 3x+5 = 26
[tex]3x + 5 \\ 3(7) + 5 \\ 21 + 5 \\ 26[/tex]
5)a+b+6 =20
[tex]a + b + 6 \\ 9 + 5 + 6 \\ 14 + 6 \\ 20[/tex]
