Here are the 4 inequality signs.

---> a is less than b

---> a is less than or equal to b

---> a is greater than b

---> a is greater than or equal to b
For the second and fourth lines above, the two sides may or may not be equal.
For the first and third lines above, the two sides cannot be equal.
Not A because regular means all sides are equal.
B has to be the answer because the others are not.
Not C because a right triangle is not regular, i.e. and equilateral triangle.
Not D because a rectangle has different side lengths.
C = children
A = adults
293 = c + a
1.50c + 2.50a = 676.50
We can use substitution to solve:
c + a = 293 subtract a to get c = 293 - a
Plug this into the second equation:
1.50(293 - a) + 2.50a = 676.50
439.5 - 1.50a + 2.50a = 676.50
439.5 + 1a = 676.50
a = 237
Substitute this into the first equation:
293 = c + 237
56 = c
For this problem your equation will be x+(x+1)+(x+2)=537
Multiply and Simplify:
x+x+1+x+2=537
3x+3=537
Subtract 3 from both sides:
3x+3-3=537-3
3x=534
Divide both sides by 3:
3x/3=537/3
x=179
179 is the middle number so: 178+179+180=537
180 is the third number.
Answer:
should be 18....
Step-by-step explanation: