Answer:
A i think
Step-by-step explanation:
Let n = cost of 1 notebook
Let p = cost of 1 pencil
Then,
3n + 4p = 8.5
5n + 8p = 14.5
You can solve for one variable in terms of the other and then substitute into the remaining equation.
3n + 4p = 8.5
+ 5n + 8p = 14.5
Multiply the top equation by -2 so that the p-containing terms cancel each other out:
-2(3n + 4p = 8.5)
+ 5n + 8p = 14.5
-n + 0 = -2.5
So after dividing both sides by -1, we see that n = $2.5. Plugging into the first equation gives p = $0.25.
3n + 4p = 8.5
5n + 8p = 14.5
The 9-sided polygon will have a central angle between the vertex and the center of one side of 360°/(2*9) = 20°. Then the apothem is
a = (6 in/2)*cot(20°) ≈ 8.242432 in
The perimeter is 9*6 in = 54 in, so the area is
A = (1/2)Pa = (1/2)*(54 in)*(8.242432 in) ≈ 222.5 in²
Step-by-step explanation:
3y + 2x - 10 = 0
in standard form
2x + 3y -10=0
||
as (ax + by - c = 0)
m = -a/b
= -2/3
or
3y + 2x - 10 = 0
make y subject
y = -2/3x + 10/3
