Explanation:
12.
76 × 1/10 = 76/10 = 7.6 tons.
7.6 + 1.4 = 9 tons
so, the tyrannosaurus weighed about 9 tons.
13.
Newton has to pay $18.95.
and Descartes has to pay $24.38.
so, together, they pay $43.33.
that means this is being deducted (subtracted) from the gift card :
50 - 43.33 = $6.67
so, there is $6.67 left on the card.