# What is the value of x in the proportion x + 1/x + 3 = 15/21

**Solution:**

Proportion definition says that when two ratios are equivalent, they are in proportion.

It is an equation or statement used to depict that two ratios or fractions are equal.

x + 1/x + 3 = 15/21

x² + 1 + 3x = 15x/21

21x² + 21 + 63x = 15x

21x² + 48x + 21 = 0

7x² + 16x + 7 = 0

x = (-16 ±√16² - 4(7)(7)) / (2× 7)

= (-16 ± √256 - 196) / 14

= -16 ±√60) / 14

= (-16 ± 2√15)/14

= -8/7 ± (√15)/7

## What is the value of x in the proportion x + 1/x + 3 = 15/21

**Summary:**

The value of x in the proportion x + 1/x + 3 = 15/21 is x = -8/7 ± √(15)/7

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