[tex]2 {}^{28} + {2}^{28} =1 \times 2 {}^{28} + 1 \times {2}^{28} = (1 + 1) \times {2}^{28} = 2 \times {2}^{28} = {2}^{1 + 28} = {2}^{29} [/tex]
