$1) 8.3^{x} + 3.2^{x} = 24 + 6^{x}$$2) 12.3^{x} + 3.16^{x} - 5^{x+1} = 20$$3) 8 - x2^{x} + 2^{3-x} - x = 0$$4) 2^{x} + 3^{x} = 1 + 6^{x}$$5) 4^{x^{2}+x} + 2^{1-x^{2}} = 2^{(x+1)^{2}} +1$$6) x^{2}.3x + 3^{x}.(12-7x) = -x^{3} + 8x^{2} -19x +12$$7) x^{2}.3^{x-1} + x.(3^{x}-2^{x})= 2.(2^{x} -3^{x-1})$