Pre-Algebra Examples

$x^{2} + 3 x + - 2 x^{2} + 9 x + 5$

Step 1

Replace all occurrences of $+$ $-$ with a single $-$ . A plus sign followed by a minus sign has the same mathematical meaning as a single minus sign because $1 \cdot - 1 = - 1$

$x^{2} + 3 x - 2 x^{2} + 9 x + 5$

Step 2

Subtract $2 x^{2}$ from $x^{2}$ .

$- x^{2} + 3 x + 9 x + 5$

Step 3

Add $3 x$ and $9 x$ .

$- x^{2} + 12 x + 5$