I) (5+3)[tex] x^{2} [/tex]=5[tex] x^{2} [/tex]+3[tex] x^{2} [/tex]+2x5x3
= 25+9+30
= 64
II) (5-3)[tex] x^{2} [/tex]=5[tex] x^{2} [/tex]-3[tex] x^{2} [/tex]+2x5x3
=25-9+30
=46
III) (5-3)(5+3)=5[tex] x^{2} [/tex]-3[tex] x^{2} [/tex]
25+15-15-9=25-9
16=16