The equal rights amendment failed to pass because it

It did not achieve ratification by the requisite 38 or three-fourths of the States.

Explanation:

The Equal Rights Amendment (ERA) failed to pass as it did not achieve ratification by the requisite 38 or three-fourths of the States. This happened in the 1970's after the rise of a strong conservative backlash against the support for  ERA and feminism. It failed because men and women would switch places which in return would be a threat to traditional roles. The other reason for its failure was that ERA would subject men and women to equal rights which meant that women would serve the country in positions such as the military; thus the heterosexual world order would collapse.

- three-quarters or two-thirds..

- "the constitution provides that an amendment may be proposed either by the congress with a two-thirds majority vote in both the house of representatives and the senate or by a constitutional convention called for by two-thirds of the state legislatures."

< 3

for this case we have the following equation:

we apply distributive property to the terms within parentheses.

subtracting 2 on both sides of the equation: