Which expression represents the algebraic phrase “nine times a number plus thirteen”? a. 9 - y + 13
b. 9 + y - 13
c. 9y + 13
d. 13y + 9

 The correct option is (C) 9y + 13.

Step-by-step explanation:  We are given to select the expression that represents the following statement :

“nine times a number plus thirteen”

Let the number be represented by y.

Then, nine times the number is written as follows :

Since we are to add 13, so the final expression is given by

Thus, the required expression is

Option (C) is CORRECT.

b. an equilateral triangle inscribed in a circle

step-by-step explanation:

we are given the figure of two circles having a triangle inside.

now, we know that,

"when a figure is lying inside an another figure, then the outside figure is known as circumscribed figure and the figure lying inside is referred to as the inscribed figure".

as we see that, the circles are containing the triangle completely.

thus, the circles are the circumscribed figures and the triangle is the inscribed figure.

hence, we get, 'an equilateral triangle is inscribed in a circle'.