Answer:
syd is 23 and dev is 69
Step-by-step explanation:
Let Dev's age be x and Syd's age be y
Since Dev is 3 times older than Syd, we may write
x
=
3
y
Since the sum of their ages is 92, we may write
x
+
y
=
92
Now replacing x with 3y, we get :
3
y
+
y
=
92
Hence
y
=
92
4
=
23
and so Syd is 23 year old.
Back substituting we get Dev is 69 years old.
Answer:
The solution is (4, 0)
Step-by-step explanation:
Using Linear combination method to solve:

Since "e" have the same coefficient in both equation with opposite operator; we will add.

Divide both side by coefficient of d which is 3

Since d = 4; put 'd' into any of the equation to get 'e'

Therefore, the solution is (4, 0)
<u>Answer:</u>
1 cm : 10.5 km
<u>Step-by-step explanation:</u>
We are given that two towns are 31.5 km in real and are 3 cm apart on a map and we are to find the scale of the map.
For this, we can use the ratio method.



Therefore, the scale of the map would be 1 cm : 10.5 km.
16 ft
Explanation
Step 1
because the ligth comes in the same angle, we have 2 similar triangles .
so,as the triangles are similar,the ratio of the shorter leg to the bigger leg must be equal.

Step 2
solve for h

therefore, the heigth of the tree is 16 ft
X= -2 and x= 2 are the answers