For this case we must raise an inequality.
We have "d" dollars initially and they are spent 12. Then:

At least 51 dollars remain, then, the sign of inequality is greater or equal in favor of the expression
, that is:

Resolving:

There are at least 63 dollars left in the account.
Answer:

Answer:
A) 0 (no solutions)
Step-by-step explanation:
Solve the equation:
3x - 10(x+2) = 13 - 7x
3x - 10x -20 = 13 - 7x
-7x - 20 = 13 - 7x
-20 = 13
Since both sides are clearly not equal to each other, no solution can satisfy both sides to be equal to each other. So A is correct.
Answer:
The answer to all of those questions would be x=-1.8
Step-by-step explanation:
7x(x + 1.8) = 0 - Distribute through the Parenthesis -
7x^2 + 12.6x = 0
x(7x + 12.6) = 0
x = 0
7x + 12.6 = 0
7x = -12.6
x = -12.6/7
x = -1.8
so x = 0 or x = -1.8
Answer:
This is a function
Step-by-step explanation:
If you do the Vertical Line Test you can see that the line passes through only one dot at a time. Therefore it is a function. If the line passed through more than one dot at a time then it wouldn't be a function.
You are given two x and y pairs: (100,45) and (570,162.5)
First solve for the slope, m.
m = (162.5 - 45) / (570 - 100)
m = 117.5 / 470
m = 0.25
Not only is "m" the slope but it is the rate (dollars per minute) in the question. So it's 25 cents per minute to use the phone.
After imputing "m" the linear equation looks like this:
y = 0.25x + b
Use either point as (x,y) to solve for the y-intercept "b". I'll use (100,45)
45 = 0.25(100) + b
45 = 25 + b
45 - 25 = b
20 = b
Not only is "b" the y-intercept but it is also always the flat fee added on to linearly increasing cost questions like this.
Final equation is:
y = 0.25x + 20
Part B.) If 939 minutes are used. Just put that in for x and solve for y.
y = 0.25(939) + 20
y = 234.75 + 20
y = 254.75