Question

The perimeter of an isosceles triangle is 12x^2-5x +4 cm find the length of one of its equal sides

Answer 1

• 4x² - x + 2

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Let the equal sides be both marked as ?

Use the perimeter formula to determine one of the equal sides.

• P = 2(?) + x(4x - 3)

Substitute the expression for the perimeter and find the value of ?

• 12x² - 5x + 4 = 2(?) + x(4x - 3)
• 12x² - 5x + 4 = 2(?) + 4x² - 3x
• 2(?) = 12x² - 5x + 4 - 4x² + 3x
• 2(?) = 8x² - 2x + 4
• ? = 4x² - x + 2

Hence the length of each of equal sides is 4x² - x + 2.