Answer: (-5,4)
When you reflect a point across the line y = x, the x-coordinate and y-coordinate change places. If you reflect over the line y = -x, the x-coordinate and y-coordinate change places and are negated (the signs are changed). the line y = x is the point (y, x).
It is given in the question that
Ann, Chang, and Kareem sent a total of 89 text messages over their cell phones during the weekend. Ann sent 9 fewer messages than Chang. Kareem sent 3 times as many messages as Ann.
Let number of messages Chang sent be x. And Ann sent 9 fewer than Chang, so Ann sent (x-9) messages. And Kareem sent 3 times as many messages as Ann, so Kareem sent 3(x-9) messages.
And the total messages are 89. That is

Combining like terms

So Chang sent 25 messages, Ann sent

And Kareem sent

-12 + 3x + 2 = 5x - 10 - 8x
-10 + 3x = -3x -10
-10 + 6x = -10
6x = 0
x = 0
Answer and explanation:
- 5 = b - 2.3 add 2.3 to both sides
+2.3 +2.3
- 2.7 = b