Answer:
Option D is the correct option.
Step-by-step explanation:
When there is a ( + ) in front of an expression in parentheses , there is no need to change the sign.
That means, the expression remains the same.
Just remove the unnecessary parentheses
⇒
Collect like terms and simplify
⇒
⇒
Hope I helped!
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The ratio is a fraction that tells us how many times longer a thing is compared to another thing. In mathematics, we express a ratio as the relationship between two numbers, namely , so the ratio can be written as:
If we can change this number without changing the ration we need to multiply both the numerator and the denominator by the same number. For instance, if we have the following ratio:
We can multiply both the numerator and denominator, say, by 7. Then:
As you can see, the ratio's number has changed but without changing the ratio itself because:
Let assume that is a rational number. Therefore it can be expressed as a fraction
where
and
.
This means that is divisible by 7, and therefore also
is divisible by 7.
So, where
Analogically to -------
is divisible by 7 and therefore so is
.
But if both numbers and
are divisible by 7, then
which contradicts our earlier assumption that
.
Therefore is an irrational number.