Answer:
Height of fir tree = 9 meters
height of pine tree= 12 meters
Step-by-step explanation:
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.
Let x be the height of fir tree and y be the height of pine tree
[tex]x+y=21[/tex]
Subtract x from both sides
[tex]y=21-x[/tex]
height of 4 fir trees = pine tree +24
[tex]4x=y+24[/tex]
Substitute 21-x or y in the above equation
[tex]4x=21-x+24[/tex]
Add x on both sides
[tex]5x=45[/tex]
Divide by 5 on both sides
x=9
Now plug in 9 for x and find out y
[tex]y=21-x[/tex]
[tex]y=21-9[/tex]
y=12
Height of fir tree = 9 meters
height of pine tree= 12 meters