-3/4
Step-by-step explanation:
f(x) = (1,2) & (-3,5)
f(x) = y²-(y¹)
_____
x²-(x¹)
y=5-2
___
-3-1
y=-3/4
The equation would be
x - 18 = collection left
X = how much was your collection before you gave your brother 13 cards
Since we don't know how big was your collection before, this would be the equation to solve it.
Example: 2x+2y=8 and 3y+2x=6
Okay so u first want to put on of the equations into a y= form. So let's use 3y+2x=6. Subtract 2x from both sides. 3y=6-2x divide by 3. Y= 6-2/3x or y= -2/3x + 6. Now just plug this new equation in for Y since "y=" into the other equation.
2x + 2(-2/3x + 6) = 8.
Then you would distribute the 2 into the parenthesis and simplify to solve for x.
After you solve for x, plug x into one of the original equations to find y.
Answer:

Step-by-step explanation:
÷ 
↓ ↓ ↓
leave it change it turn it over
× 
now solve it
×
= 
now simplify it
= 
Answer:
300pi
Step-by-step explanation:
that is 3/4 of a circle with the radius of 20. Meaning that the area is 300pi