Algebra Examples

$- 7 x^{2} + 1 - - 2 x^{2} - 4 x$

Step 1

Replace all occurrences of $-$ $-$ with a single $+$ . Two consecutive minus signs have the same mathematical meaning as a single plus sign because $- 1 \cdot - 1 = 1$

$- 7 x^{2} + 1 + 2 x^{2} - 4 x$

Step 2

Add $- 7 x^{2}$ and $2 x^{2}$ .

$- 5 x^{2} + 1 - 4 x$