fix typo

Author: asukaminato0721

src/math/p5.Vector.js

@@ -791,7 +791,7 @@ p5.Vector = class {
  *
  * If only one value is provided, as in `v.mult(2)`, then all the components
  * will be multiplied by 2. If a value isn't provided for a component, it
- * won't change. For example, `v.mult(4, 5)` multiplies `v.x` by, `v.y` by 5,
+ * won't change. For example, `v.mult(4, 5)` multiplies `v.x` by 4, `v.y` by 5,
  * and `v.z` by 1. Calling `mult()` with no arguments, as in `v.mult()`, has
  * no effect.
  *