Simplify the expression 5(a+3)

5a + 15

Step-by-step explanation:

To simplify, simply distribute 5 to all terms within the parenthesis. Multiply in this case:

5(a + 3):

5 * a = 5a

5 * 3 = 15

5a + 15 is your answer.

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540°

Step-by-step explanation:

Just divide the shape into triangles and count the number of triangles. This is what your formula is doing for you. It's telling you how many triangles make up the shape and then multiplying that number by 180 degrees to find the sum of your interior angles.