Question

plz tell the solution​

Answer 1

Answer:

then answer is 3

Step-by-step explanation:

5^x+15(5)^0+5^2+4(5^x) =665

~(5^0)=1

5^x+4(5^x) +15+25=665

5^x+4(5^x) =665-625

5^x+4(5^x)=625

5^x(1+4)=625

5^x(5)=625

5^x=625/5

5^x=125

5^x=5^3

x=3