Answer:
The x-coordinate of A is:
a = 6.1
Step-by-step explanation:
For point A:
x-coordinate = a
x-coordinate + y-coordinate = 14
y-coordinate = 14 - x-coordinate
y-coordinate = 14 - a
So point A can be written as (a, 14-a)
Let (a,14) be (x₁,y₁)
Point P can be written as (3a, a²+13a-11)
Let P be (x₂,y₂)
Slope of a line passing through 2 point is given as:
where m=7
Substitute all values
As A has only positive coordinates
a = 6.1
X - number of 5 c stamps,
y - number of 15 c stamps,
z - number of 25 c stamps.
The system:
x + y + z = 160
y = 3 x
0.05 x + 0.15 y + 0.25 z = 25 / * 100
-------------------------------------------------
x + y + z = 160
y = 3 x
5 x + 15 y + 25 z = 2500 / : 5
----------------------------------------
x + 3 x + z = 160
x + 3 y + 5 z = 500
-------------------------
4 x + z = 160 / * ( - 1 )
10 x + 5 z = 500 / : 5
------------------------------
- 4 x - z = - 160
+
2 x + z = 100
-------------------------
- 2 x = - 160
x = 30, y = 90
z = 160 - 120 = 40
Answer:
- 30 of 5 c stamps,
- 90 of 15 c stamps,
- 40 of 25 c stamps.
Answer:
Step-by-step explanation: