1) a) (x+2)^2 =x^2+4x+4
b) (3y-x)^2 = 9y^2-6xy+x^2
2) 28*32=(30-2)(30+2)=(30^2-2^2 = 900-4=896
67*73=(70-3)(70+3)=70^2-3^2=4900-9=4891
3) 3(x+1)(x-1) = 2(x-2)(x+2) + x^2 +2x
3(x^2-1)=2(x^2 - 2^2) +x^2+2x
3x^2- 3 = 2x^2 - 8 + x^2 + 2x
3x^2 - 3x^2 -2x = -8 + 3
-2x = -5
x= 2,5