The combined height of one fir tree and one pine tree is 21 meters. The height of 4 fir trees stacked on top of each other is 24 meters taller than one pine tree.

Fir tree = 9

Pine tree = 12

Step-by-step explanation:

I'm assuming you need the height of the pine and fir tree.

Set the height of the pine tree to p and the height of the fir tree to f.

Now set up equations:

The combined height is 21 -

f + p = 21

4 fir trees is 24 taller than 1 pine tree -

4f = p + 24

Subtact 24 from both sides

4f - 24 = p

Now substitute 4f - 24 = p into the first equation

f + (4f - 24) = 21

SImplify:

f + 4f - 24 = 21

5f - 24 = 21

Add 24 on both sides

5f = 45

Divide by 5 on both sides

f = 9

The height of the fir tree is 9 meters.

Now put the 9 into the f + p = 21

f + p = 21

9 + p = 21

Subtract 9 on both sides

p = 12

The pine tree is 12 meters tall.