How do you do this question?

Answer:
∫₁⁵ 2t (t² + t³) dt
Step-by-step explanation:
The area is ∫ₓ₁ˣ² y dx. To parameterize, replace x₁ and x₂ with t₁ and t₂. Replace y = f(x) with y = f(t), and replace dx with (dx/dt) dt.
x = 5 + t², so dx = 2t dt.
∫₁⁵ (t² + t³) (2t dt)
∫₁⁵ 2t (t² + t³) dt