1.D 2. A 3.C 4.D
1 Is the monomial as it only contains one expression.
2. Is the difference of squares because something squared minus something squared.
3. Is standard because it is of the form

4. We know D is the not the monomial simply because its power is negative which means it does not fit the definition of a polynomial.
In geometry, the definition of a triangle is a two-dimensional closed figure with three sides. Aside from this, it is proven that the sum of the angles of a triangle is 180°. This is a triangle's innate property. Therefore, any closed shape with three sides is a triangle and it follows that the sum of the three angles is equal to 180°.
It is logical therefore, that the first step in proving this is by using the definition of a triangle.
5/7 +1/3
find the common denominator for both of the fractions
common denominator is 21
mutiply by 3 for 5/7
(5)(3)/(7/(3)= 15/21
mutiply by 7 for 1/3
(1)(7)/(3)(7)= 7/21
15/21+7/21
add the numerators
15+7= 22
denominator stays the same -21
Answer:
22/21 or 1 1/21