Because empty set has no element which automatically make it a subset of every set.
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So you would do 5*2x +5*-8 +15=-15
Then simplify so it would be 10x + -40 + 15 = -15
Then add -40 and 15 together
Then it would be 10x + -25 = -15
Then add 25 to -25 and -15
So it would be 10x = 10
And then divide 10 from 10 with would be 1 so x = 1
Answer:

Step-by-step explanation:
Let the initial altitude ( in meters ) =
,
Since, altitude is increasing at a constant rate of 740 meters per hour.
So, the final altitude ( say A ) in meters after t hours = initial altitude + increment in altitude in t hours,

According to the question,
A = 710 meters, when t = 1.5 hours,



Hence, the required equation that shows the relationship between the altitude and number of hours,

Answer:
Each solution is a pair of numbers (x,y) that make the equation true. Solving a linear equation usually means finding the value of y for a given value of x. If the equation is already in the form y = mx + b, with x and y variables and m and b rational numbers, then the equation can be solved in algebraic terms.
definition. hope it helps
Step-by-step explanation: