Answer:
t = 5
Step-by-step explanation:

Subtract 19 from 39
Divide by 4
2000 smartphones and 1500 flip phones
4-3=1
1x500=500
500x4=2000
500x3=1500
Answer:
There are 16 Oak tree in the forest.
Step-by-step explanation:
Given: There are 4 Oak tree on every 10 pine trees.
There are total 24 more pine tree than Oak tree.
Using the ratio of trees to find the number of trees.
Lets assume there are total number of Oak tree be "x".
∴ Total number of Pine trees will be 
We know the ratio of Oak to Pine tree is 4:10 or 
⇒
Multiplying both side by 
⇒ 
Using distributive property of multiplication, distributing 4 with x and 24.
⇒ 
Multiplying both side by 10
⇒ 
subtracting both side by 4x
⇒ 
dividing both side by 6
⇒
∴ 
Hence, There are 16 Oak trees in the forest.
Answer:
-3=(1/2)(2)+3
Step-by-step explanation:
Since they are right triangles use Pythagorean Theorem.
a^2 + b^2 = c^2 where c is the hypotenuse.
a. 12^2 + b^2 = 13^2
144 + b^2 = 169
subtract 144 from both sides
b^2 = 25
take the square root of both sides
t = 5 This is also know as a Pythagorean Triple 5-12-13
b. a^2 + 9^2 = 12^2
a^2 + 81 = 144
subtract 81 from both sides
a^2 = 63
take the square root of both sides
a = √63
a = √(9 * 7)
a = 3√7
c. 6^2 + 9^2 = c^2
36 + 81 = c^2
117 = c^2
take the square root of each side
c = √117
c = √(9*13)
x = 3√13