Answer:
47 ducks and 7 cows
Step-by-step explanation:
Ducks have 2 legs and cows have 4 legs.
If all the animals are ducks,
number of legs= 54(2)= 108
Difference in number of legs= 122 -108= 14
Difference in no. of legs per animal= 4 -2 = 2
Number of cows=14 ÷2 = 7
Number of ducks= 54-7= 47
Thus, he have 47 ducks and 7 cows.
Let's check:
Total number of feet= 7(4)+ 47(2) = 122 ✓
You could also first assume that all the animals are cows. The answer would be the same.
let's bear in mind that
standard form for a linear equation means
• all coefficients must be integers, no fractions
• only the constant on the right-hand-side
• all variables on the left-hand-side, sorted
• "x" must not have a negative coefficient
so, let's do away with the denominators by multiplying both sides by the LCD of all fractions, in this case 6.

Answer:
The answer is 13x-7
Step-by-step explanation:
f(x) is x-7, and g(x) is 4x3. 4x3 can also mean 12x , because 4x3 is 4*x*3. So, f(x) can be replaced with x-7, and g(x) can be replaced by 12x. (x-7)+(12x) is 13x-7.