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consider -/8+x

a) Find a value for x that would make this number rational

b) find a value that would make this number irrational

1 answer

a) To make the number rational, we need the expression to be a terminating or repeating decimal. This means we need to find a value for x such that the expression results in a fraction.

In order to achieve this, we can express the expression as a fraction by finding a common denominator for 8 and x. The common denominator is 8x.

The expression becomes: 8/8x + x/8x

Combining both terms, we get: (8 + x) / 8x

Now, in order for the expression to be rational, 8 + x must be divisible by 8x.

One possible value for x that satisfies this condition is x = 1.

Plugging x = 1 into the expression, we get: (8 + 1)/8(1) = 9/8, which is a rational number.

b) To make the number irrational, we need the expression to result in a decimal that cannot be expressed as a fraction.

One way to achieve this is to choose a value for x that makes the expression equal to an irrational number, such as π or √2.

For example, if we choose x = π, the expression becomes: 8/8π + π/8π

Simplifying, we get: (8π + π) / 8π

This expression cannot be further simplified into a fraction and therefore the resulting number is irrational.