Answer:
f(-1) = 0
f(2) = 16
Step-by-step explanation:
f(-1) = 4(-1) + 4 = 0
f(2) = 4(2) + 8 = 16
Answer:
16=3f+2m
16-2m=3f
Step-by-step explanation:
Answers:
- Total equation: x+y = 80
- Legs equation: 2x+4y = 248
- How many ducks? 36
- How many cows? 44
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Further explanation:
- x = number of ducks
- y = number of cows
x+y = 80 is the total equation (ie the head count equation) since we assume each animal has 1 head, and there are 80 heads total.
That equation can be solved to y = 80-x after subtracting x from both sides.
The legs equation is 2x+4y = 248 because...
- 2x = number of legs from all the ducks only
- 4y = number of legs from all the cows only
- 2x+4y = total number of legs from both types of animals combined
We're told there are 248 legs overall, so that's how we ended up with 2x+4y = 248
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Let's plug y = 80-x into the second equation and solve for x.
2x+4y = 248
2x+4( y ) = 248
2x+4( 80-x ) = 248
2x+320-4x = 248
-2x+320 = 248
-2x = 248-320
-2x = -72
x = -72/(-2)
x = 36
There are 36 ducks
Now use this x value to find y
y = 80-x
y = 80-36
y = 44
There are 44 cows.
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Check:
36 ducks + 44 cows = 80 animals total
36*2 + 44*4 = 72 + 176 = 248 legs total
The answers are confirmed.
Step-by-step explanation:
Given,
x = y - 3
Also,
6(y - 3) = 3y + 6
6y - 18 = 3y + 6
6y - 3y = 6 + 18
3y = 24
y = 24/3
y = 8
x = 8 - 3
x = 5
Therefore, the first number is 5 and the second number is 8.
Okay. so we need 15 2/5 pound bags. We'll calculate how many pounds that actually comes to. Our problem is 15x2/5. Using cross simplification, our problem becomes 3x2. 3x2=6. We need 6 pounds. That means that we must have 6 1-pound bags to fit with no leftovers.