Answer: f^{-1}(x) = 3-x/3
Step-by-step explanation: Let y = f(x) and rearrange making x the subject, that is...
1. y = - 3x + 3 ( add 3x to both sides )
2. 3x + y = 3 ( subtract y from both sides )
3. 3x = 3 - y ( divide both sides by 3 )
4. x = 3-y/3
Change x back into terms of y
f^{-1}(x) = 3-x/3
Answer:
Associative property - addition
Step-by-step explanation:
When three or more numbers are added, the sum is the same regardless of the way in which the numbers are grouped.
(6+2) + 5 = 6 + (2+5)
8 + 5 = 6 + 7
13 = 13
Answer:
50 of D and 10 of C
Step-by-step explanation:
First of all, put this data into 2 equations.
You sold 60 items, so C+D=60
C is $5 so we can represent it by 5C
D is $7 so we can represent it by 7D
You made $400 total from C and D, so 5C+7D=400
We can use simultaneous equations to solve this.
To eliminate one of these variables, we'll multiply the first one by 5 to make it 5C like the other.
5(C+D=60) (make sure you multiply both sides.)
so 5C+5D=300
5C+7D=400
Now we solve it:
5C-5C+7D-5D=400-300
7D-5D=100
2D=100
D=50
Now we can substitute this with one of the equations to find C
C+50=60
C=60-50
C=10
so, (10x5)+(50x7)=400
Answer:
x = -4 y =-4
Step-by-step explanation:
Solve for the first variable in one of the equations, then substitute the result into the other equation.