Answer:
The age of the grinkgo tree is 10 years old and the age of the dogwood tree is 4 years old
Step-by-step explanation:
Let
x -----> the age of the grinkgo tree
y -----> the age of the dogwood tree
z -----> the age of the blue spruce tree
we know that
[tex]x=3y-2[/tex] ------> equation A
[tex]z=8[/tex] ----> equation B
[tex]x=\frac{1}{2}(y+2z)[/tex]
substitute the value of z
[tex]x=\frac{1}{2}(y+2(8))[/tex]
[tex]x=\frac{1}{2}(y+16)[/tex] -----> equation C
equate equation A and equation C and solve for y
[tex]3y-2=\frac{1}{2}(y+16)[/tex]
[tex]6y-4=(y+16)[/tex]
[tex]6y-y=16+4[/tex]
[tex]5y=20[/tex]
[tex]y=4[/tex]
Find the value of x (equation A or equation C)
[tex]x=3(4)-2=10[/tex]
therefore
The age of the grinkgo tree is 10 years old and the age of the dogwood tree is 4 years old