Question

Miss Sullivan owns a farm where she has a total of 28 birds and dogs the total number of legs on those animals is 70 how many dogs and how many birds are on the farm

Answer 1

Answer:

21 birds and 7 dogs

Step-by-step explanation:

Represent Birds with B and Dogs with D

$B + D = 28$ ----- Total Animals

A bird has 2 legs and a dog has 4, so:

$2B + 4D = 70$ ---- Legs

Required

Solve for D and B

Make D the subject in the first equation

$D = 28 - B$

Substitute 28 - B for D in the second

$2B + 4(28 - B) = 70$

$2B + 112 - 4B = 70$

Collect Like Terms

$2B - 4B = 70 - 112$

$-2B = -42$

Solve for B

$B = -42/-2$

$B = 21$

Recall that: $D = 28 - B$

$D = 28 - 21$

$D = 7$

Hence, there are 21 birds and 7 dogs