Answer:
x= 16 and y = 9
Step-by-step explanation:
1 st equation ; x+y = 25
2 nd equation ; x- y = 7
from 1 st equation
x = 25 - y
now putting value of x in 2 nd equation
x- y = 7
25 - y-y = 7
25 -2y =7
25-7 = 2y
18 = 2y
18/2 = y
y = 9
again
putting value of y in 1 st equation
x = 25-y
x = 25-9
x= 16
Answer:
16 years
Step-by-step explanation:
Given data
For the first tree
let the expression for the height be
y=4+x--------------1
where y= the total height
4= the initial height
x= the number of years
For the second tree, the expression is
y=12+0.5x-------------2
Equate 1 and 2
4+x=12+0.5x
x-0.5x=12-4
0.5x= 8
x= 8/0.5
x=16
Hence it will take 16 years for both trees to have the same height
Let h = height
h square = 20 square + 5 square
h square = 400+ 25
So you square root both sides
h = root 425
h = 20.6155281