mohon bantuannya ya ka

15/(√2+√7) × (√2-√7)/(√2-√7)
= 15(√2-√7) / (2 - 7)
= 15(√2 - √7) / -5
= -3(√2 - √7)
= -3√2 + 3√7
= 3√7 - 3√2