SOLUTION: Hi, I'm currently on binomials. What should I do to solve this? "When (3a+x2)6 is expanded, the coefficient of the term in x4 is 19440. Find the value of a."

Algebra ->  Quadratic Equations and Parabolas  -> Quadratic Equations Lessons  -> Quadratic Equation Lesson -> SOLUTION: Hi, I'm currently on binomials. What should I do to solve this? "When (3a+x2)6 is expanded, the coefficient of the term in x4 is 19440. Find the value of a."       Log On


   

Question 853999: Hi, I'm currently on binomials. What should I do to solve this?
"When (3a+x2)6 is expanded, the coefficient of the term in x4 is 19440. Find the value of a."

Found 2 solutions by ewatrrr, Vladdroid:
Answer by ewatrrr(24785) About Me  (Show Source):
You can put this solution on YOUR website!
729x^6 + 1458a^5x^2 + 1215a^4x^4 ....
19440/1215 = 16 ⇒ a^4 = 16, a = 2

Answer by Vladdroid(91) About Me  (Show Source):
You can put this solution on YOUR website!
729x^6 + 1458a^5x^2 + 1215a^4x^4 ....
19440/1215 = 16 ⇒ a^4 = 16, a = 2