Find the complete factorization of the expression. 15xz + 21yz a) 3z(5x + 7y) b) 3xy(5z + 7z) c) z(15x + 21y) d) 3(5xz + 7yz)

Idon’t understand this.. will someone ? will mark brainliest along with 20 points.

What is the result of converting 60 ounces to pounds remember there are 16 ounces in a pound

The fence around a quadrilateral-shaped pasture is 3a^2+15a+9 long. three sides of the fence have the following lengths: 5a, 10a-2, a^2-7. what is the length of the fourth side of the fence?