[tex]\dfrac 25(d-10) - \dfrac 23(d+6)\\\\\\=2 \left(\dfrac{d-10}5 - \dfrac{d+6}3 \right)\\\\\\=2\left[\dfrac{3(d-10) - 5(d+6)}{15}\right]\\\\\\=2 \left( \dfrac{3d-30-5d-30}{15} \right)\\\\\\=2\left(\dfrac{-2d-60}{15} \right)\\\\\\=2(-2) \left(\dfrac{d+30}{15} \right)\\\\\\=-4 \left(\dfrac{d+30}{15} \right)\\\\\\=-4\left(\dfrac d{15} +2 \right)\\\\\\=-\dfrac{4d}{15}-8[/tex]
