Please choose the correct ending to complete the given sentence: Computers and Electronics: [header] How to solve quadratic equations with the " transforming method " [title] Recall the rule of signs. [substeps] If a and c have different signs, roots have different signs if a and c have same sign, roots have same sign. If a and b have different signs, both roots are positive.

Ending1: [title] Recognize the " exponential " equation, which combines two objects together. [substeps] Reconstitution is where 1 object continuously compares itself to another or an existing force. Ending2: " color-blind " means that all the signs are positive. The two may have different signs in the equation, but there is no change or confusion. Ending3: Should 10 stop the two different signs before the correct sign started, what might happen, would stop the two with the same sign before the differences could not be reversed. [title] [title] Try to solve the quadratic equation. Ending4: If a and b have same sign, both roots are negative. [title] Transform the equation in standard form ax^2 + bx + c = 0 (1) into a new equation, with a = 1, and the constant c = a * c.

Answer format: ending1/ending2/ending3/ending4