Answer:
5x + 15x²
Step-by-step explanation:
Given the expression 5x(1+3x)
Generally, according to the distribution rule,
A(B+C) = AB + AC
A is distributed over B and C
Similarly,
5x(1+3x)
= 5x(1) + 5x(3x)
= 5x + 15x²
Hence the expression required is 5x + 15x²
