Question

5 ^ x+3.25^x+2.5^x=125

Answer 1

5^(x+3) . 25^(x+2) . 5^x = 125           coloque tudo na base 5:
5^(x+3) . (5^2)^(x+2) . 5^x = 5^3
5^(x+3) . 5^(2x+ 4) . 5^x = 5^3
x + 3 + 2x + 4 + x = 3
4x + 7 = 3
4x = 3 - 7
4x = - 4
x = -4/4
x = -1