When you are multiplying an exponent by an exponent that is outside the parentheses you multiply the exponential values together (Remember the power rule (b^n)^m
= b^(n*m)?). Then add the 4 (Remember product rules a^n*a^m = a^(n+m)?)
[tex]( y^{3})^{5}* y^{4} = (y^{15} )* y^{4}= y^{19} [/tex]
Your answer is B. y^19
