Final answer:
The given trigonometric expression is transformed using the sine addition formula to become sin(110°).
Step-by-step explanation:
The expression sin(70°)cos(40°) + cos(70°)sin(40°) is equivalent to sin(70° + 40°) based on the sine addition formula, which is sin(a + ß) = sin(a)cos(ß) + cos(a)sin(ß). By applying the formula to our given expression, we simply add the angles inside the sine functions, resulting in sin(110°), which is the equivalent expression.