There are 7 animals a farmer's field. some are cows and some are chickens. the farmer counts 18 legs in all.

2 cows and 5 chickens.

Step-by-step explanation:

NOTE: This will be solved using simultaneous equations.

Let x = cows and y = chickens

1. form two equations

4x + 2y = 18 ... (1)

x + y = 7 (2)

2. make y (or x) the subject of one equation

x + y = 7

y = 7 - x ... (3)

3. Substitute (3) into (1)

4x + 2( 7 - x) = 18

4. solve for x

4x + 14 - 2x = 18

2x = 4

x = 2

5. Now substitute x value into equation (2)

x + y = 7

2 + y = 7

y = 5

∴ cows (x) = 2

chickens (y) = 5

answer:

a=9

step-by-step explanation: lmk if you need a explanation