Answer:
There 11 cows and 6 ducks in the meadow.
Explanation:
Given,
Total number of legs = 56
Total number of heads = 17
Solution,
Let the number of cows be 'c'.
And also let the number of ducks be 'd'.
We know that all the animals have 1 head.
So we can say that the total number of heads is equal to number of number of cows and number of ducks.
we can frame it as;
![c+d=17\ \ \ \ equation\ 1](https://img.qammunity.org/2021/formulas/mathematics/high-school/lwnnfh95vmbubkt59s9p15xniz7zmofnnt.png)
Again we know that cows have four legs and ducks have two legs.
So total number of legs is equal to number of cows multiplied by 4 plus number of ducks multiplied by 2.
framing in equation form, we get;
![4c+2d=56](https://img.qammunity.org/2021/formulas/mathematics/high-school/omkytyp01vjn0lp2s0t8e3ik5mi4c91zgi.png)
On dividing both side by '2' using division property, we get;
![(4c+2d)/(2)=(56)/(2)\\\\2c+d=28\ \ \ \ equation\ 2](https://img.qammunity.org/2021/formulas/mathematics/high-school/rho04pqy0wh6u9bimmi0q3fgr1ggx03sqd.png)
Now Subtracting equation 1 from equation 2 we get;
![2c+d-(c+d)=28-17\\\\2c+d-c-d=11\\\\c=11](https://img.qammunity.org/2021/formulas/mathematics/high-school/3bp5mr43pwm3wkoydja8xne4k9nr2uyvh2.png)
Substituting the value of c in equation 1 we get;
![c+d=17\\\\11+d=17\\\\d=17-11=6](https://img.qammunity.org/2021/formulas/mathematics/high-school/o8pdu0t74ezm6j82w9dqle5sdj93n1f5ra.png)
Hence There 11 cows and 6 ducks in the meadow.