Please help If you vertically stretch the exponential function f(x)=2^x by a factor of 5, what is the equation of the new function A.f(x)=5(2^x)B.f(x)=10^xC.f(x)=7^xD.f(x)=2^(5x)

A vertical stretch of f(x) by a scale factor of a is 
g(x)=a f(x)

For [tex]f(x)=2^x[/tex], and a=5
the vertically stretched function is then
[tex]g(x)=a f(x)=5*2^x[/tex]