D. Because you're multiplying 3 by a number which is what the variable represents (n), then you're just adding 7 to that which equals 19 all together. It all translates to 3n+7=19.
I would draw the triangle then it would be easier to answer. It is not an equilateral because it is not equal on all sides. Perhaps scalene because all the sides are not the same.
Answer:
expanded form: 5 * 5 * 5
value: 125
Step-by-step explanation:
