Ariana started a savings account with $240. She deposits $30 into her account at the end of each month. She wants to know how ma
1 answer:
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Answer with Step-by-step explanation:
1. We are given that an expression
We have to prove that this expression is always is even for every integer.
There are two cases
1.n is odd integer
2.n is even integer
1.n is an odd positive integer
n square is also odd integer and n is odd .The sum of two odd integers is always even.
When is negative odd integer then n square is positive odd integer and n is negative odd integer.We know that difference of two odd integers is always even integer.Therefore, given expression is always even .
2.When n is even positive integer
Then n square is always positive even integer and n is positive integer .The sum of two even integers is always even.Hence, given expression is always even when n is even positive integer.
When n is negative even integer
n square is always positive even integer and n is even negative integer .The difference of two even integers is always even integer.
Hence, the given expression is always even for every integer.
2.By mathematical induction
Suppose n=1 then n= substituting in the given expression
1+1=2 =Even integer
Hence, it is true for n=1
Suppose it is true for n=k
then is even integer
We shall prove that it is true for n=k+1
=
=
=Even +2(k+1)[/tex] because is even
=Sum is even because sum even numbers is also even
Hence, the given expression is always even for every integer n.
That's the answer in my opinion.good luck!
Answer:
Therefore the value of x = 10 units
Step-by-step explanation:
Let label the Triangles first,
Δ ABC a right triangle at ∠ A =90°
Δ ADB andΔ ADC a right triangle at ∠ D =90°
Such that
AD = x
BD = 50
CD = 2
∴ BC = BD + DC = 50 + 2 = 52
To Find:
x = ?
Solution:
In right triangle By Pythagoras Theorem,
In right triangle Δ ADB andΔ ADC By Pythagoras Theorem we will have,
AB² = BD² + AD²
AB² = 50² + x² ..................equation ( 1 )
and
AC² = DC² + AD²
AC² = 2² + x² ...................equation ( 2 )
Now in right triangle Δ ABC,
BC² = AB² + AC²
Equating equation (1 ) and ( 2 ) and the given value we get
52² = 50² + x² + 2² + x²
∴ 2x² = 2704 - 2504
∴ 2x² =200
∴
Therefore the value of x = 10 units
