300 messages would have to be sent or received in order for the plan to cost same each month.
Step-by-step explanation:
Given,
Cost per month = $30
Per text sent or received charges = $0.10
Let,
x be the number of texts sent or received.
A(x) = 0.10x+30
A comparable plan costs = $60 per month
Text messages are unlimited.
B(x) = 60
For the two plans to cost equal;
A(x) = B(x)

Dividing both sides by 0.10

300 messages would have to be sent or received in order for the plan to cost same each month.
Keywords: function, addition
Learn more about functions at:
#LearnwithBrainly
1. The fourth graph: D
2. The first graph: A
Answer: See explanation
Step-by-step explanation:
15.) -7x + 6 (x - 8/2) - 2(x + 3) + 10
-7x + 6 (x - 4) - 2(x + 3) + 10
-7x + 6x - 24 - 2x - 6 + 10
Bring like terms together
-7x + 6x - 2x - 24 - 6 + 10
-3x - 20
16.) B, C, D
B. 3 (x + 2) + 4x
3x + 6 + 4x = 7x + 6
C. -2 + 4(x + 3)
-2 + 4x + 12 = 4x + 10
D. 3x + 5(x - 1)
3x + 5x - 5
8x - 5
17.) A, B, D
A. 1/5(x - 50)
1/5x - 10
B. 1/6(-x + 12)
-1/6x + 2
D. 1/2(x + 16)
1/2x + 8