It's a simultaneous equation:
Steps:
1.Number the equations..
a+b=77 -1
a-b=13 -2
2. Choose what variable you want to use. In this case I would use the "b". Since the signs in front of the "b's" are different, add the two equations together
a + b = 77
+ + +
a (-b) = 13
Which gives;
2a = 90
Then solve to find a:
2a=90
a= 90/2
a=45
3.Then plug the "a" value into any of the original equations to find the "b" value. I would use equation 1 since the all the variables are positive.
a + b = 77
(45) + b = 77
b=77-45
b=32
4.Solution
a=45
b=32
The point-slope equation of the line is
Step-by-step explanation:
The form of the point-slope equation is , where
- m is the lope of the line
- is a point lies on the line
The slope of a line , where
and are two points on the line
∵ The line through (2 , 3) and (7 , 4)
∴ = 2 and = 7
∴ = 3 and = 4
- Substitute these value in the rule of the slope
∵
∴ the slope of the line is
Let us substitute the value of the slope and the coordinates of point in the form of the equation
∵
∵ = 2 and = 3
∵
∴
The point-slope equation of the line is
Learn more:
You can learn more about the linear equation in brainly.com/question/12941985
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Answer:
Step-by-step explanation:
Answer: We should add the constant 81 to the expression to have a perfect square trinomial.
The perfect square trinomial that would be formed would result from (x + 9)^2.
We can use foil to prove it.
(x + 9)(x + 9)
x^2 + 9x + 9x + 81
x^2 + 18x + 81
81 is the value that must go with 18x in the middle to form the perfect square trinomial.
This cash flow is a perpetuity. To find the present value of perpetuity, we use the equation of
Pv=C÷r
Pv=39,000÷0.058
Pv=672,413.79