Will mark brainliest!!! Solve for x and plz do both
1 answer:
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Answer:
1) {y,x}={-3,-23}
2) {x,y}={7,-9/2}
Step-by-step explanation:
Required:
- Solve systems of equations
1) y - x = 20, 2x - 15y = -1
Equations Simplified or Rearranged :
[1] y - x = 20
[2] -15y + 2x = -1
Graphic Representation of the Equations :
x + y = 20 2x - 15y = -1
Solve by Substitution :
// Solve equation [1] for the variable y
[1] y = x + 20
// Plug this in for variable y in equation [2]
[2] -15•(x +20) + 2x = -1
[2] - 13x = 299
// Solve equation [2] for the variable x
[2] 13x = - 299
[2] x = - 23
// By now we know this much :
y = x+20
x = -23
// Use the x value to solve for y
y = (-23)+20 = -3
Solution :
{y,x} = {-3,-23}
2) 25-x=-4y,3x-2y=30
Equations Simplified or Rearranged :
[1] -x + 4y = -25
[2] 3x - 2y = 30
Graphic Representation of the Equations :
4y - x = -25 -2y + 3x = 30
Solve by Substitution :
// Solve equation [1] for the variable x
[1] x = 4y + 25
// Plug this in for variable x in equation [2]
[2] 3•(4y+25) - 2y = 30
[2] 10y = -45
// Solve equation [2] for the variable y
[2] 10y = - 45
[2] y = - 9/2
// By now we know this much :
x = 4y+25
y = -9/2
// Use the y value to solve for x
x = 4(-9/2)+25 = 7
Solution :
{x,y} = {7,-9/2}
Answer:
The function have a constant ratio
No, it does not represent an exponential function.
Step-by-step explanation:
As given,
Ines has saved $5. She doubles the amount she saves each week.
⇒ In first week she saved = $5
In second week she saved = 2×$5 = $10
In third week she saved = 2×$10 = 20
In fourth week she saved = 2×$20 = 40
and so on..
∴ we get the series
5, 10, 20, 40 ,.......
If the series is given as a, b, c, d, ..... , then
The common difference is defined as d = b-a = c-b
The common ration is defined as r =
Here, in the given question
The series is - 5, 10, 20, 40
This has no common difference , d = 10 - 5 (= 5 )≠ 20 - 10 (= 10)
As 5 ≠ 10
So the function does not define common difference .
Now,
This has common ratio , r =
As 2 = 2
So, the function represent common ratio
Now,
The function does not represent an exponential function because it is increased by common ratio.