1x=-1
that means whererever you see x, you replace it with -1
x is a placeholder for an unknown number
so repolace it
-1+5=4
5-1=4
true
Answer:

Step by step explanation:
Let d represent the rate of temperature decrease in degrees Celsius per day from Monday to Thursday.
As temperature decreased at a constant rate in the next 3 days, so the rate of temperature will decrease 3d degree Celsius in 3 days.
We are told that the pool was open on Monday. The high temperature was
on Monday. So the decrease in temperature from Monday to Thursday will be
.
We have been given that the swimming pool is open when the high temperature is higher than
.
As the pool was closed on Thursday. This means that temperature on Thursday was less than or equal to 20 degree Celsius. We can represent this information in an inequality as:

Therefore, the inequality
can be used to determine the rate of temperature decrease in degrees Celsius per day, d, from Monday to Thursday.
Step-by-step explanation:
sum of all angles = 360
7x-4 = 360
7x= 364
x = 52
angle j = 150
angle k = 62
angle m = 100
I think you subtitute de 34 by x not sure
9514 1404 393
Answer:
The equation should be 8 (x minus 2.75) = 78, and she needs to sell each necklace for $12.50.
Step-by-step explanation:
The contribution margin of each necklace is the difference between its selling price (x) and its cost (2.75). Then the total profit from 8 necklaces would be ...
8(x -2.75)
If Rita wants that profit to be $78, then she needs to solve the equation ...
8(x -2.75) = 78 . . . . correct equation
The solution is ...
x -2.75 = 9.75 . . . . divide by 8
x = 12.50 . . . . . . . . add 2.75
She needs to sell each necklace for $12.50.