No, one, or infinitely many solutions

one, no, one, infinitely

Step-by-step explanation:

a. you can get 7x = 21 - 21 = 0 ==> x = 0

b. subtract 12x from both sides ==> get 15 = -15, which is not true

c. -5x-5x=25+25 ==> -10x = 50 ==> x = -5

d. get -2x -6 -7 = -2x - 6 - 7 ==> so it's infinitely

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'.

answer: dead jah

step-by-step explanation:

bullet + jah= dead jah