### Home > INT3 > Chapter 10 > Lesson 10.3.2 > Problem10-169

10-169.

What is the third term of $( 2 x + \frac { 1 } { 4 x } ) ^ { 7 }$?

What is the third term in the expansion of $(a + b)^7$?

$21a^5b^2$

Substitute $2x$ for $a$ and $\frac{1}{4x}$ for $b$, and simplify.