When Billy's asked how old he is, he replies, "In two years i will be twice as old as i was 5 years ago." How old is he?
Answers
12 years old.
• Let the present age of Billy be represented by x.
• In two years, Billy will be: = x + 2
• Since in 2 years, he will be twice as old as he was 5 years ago, this will be:
x + 2 = 2(x - 5)
The equation to solve the question is:
x + 2 = 2(x - 5)
x + 2 = 2x- 10
Collect like terms
2x - x = 2 + 10
x = 12
• Billy is 12 years old.
Related Questions
One of the legs of a right triangle measures 2 cm and its hypotenuse measures 9 cm. Find the measure of the other leg. If necessary, round to the nearest tenth.
Answers
Answer:
The measure of the other leg = 8.8 cm
Explanation:
Given - One of the legs of a right triangle measures 2 cm and its hypotenuse measures 9 cm.
To find - Find the measure of the other leg.
Proof -
We know that,
For a right angle triangle,
Apply The Pythagoras Theorem , which states that
(Hypotenuse)² = (Base)² + (Perpendicular)²
Given that,
Hypotenuse = 9 cm
One leg = 2 cm
Let us assume that,
One leg is base and another leg is Perpendicular.
We also can suppose vice-verse, it does not affect the solution.
Now,
(Hypotenuse)² = (Base)² + (Perpendicular)²
⇒(9)² = (2)² + (Perpendicular)²
⇒81 = 4 + (Perpendicular)²
⇒81 - 4 = (Perpendicular)²
⇒77 = (Perpendicular)²
⇒√77 = Perpendicular
⇒Perpendicular = 8.775 ≈ 8.8
∴ we get
The measure of the other leg = 8.8 cm
