Solve 2-a-a*a

$$2 - a - a \times a$$

Factor

$$\left(1-a\right)\left(a+2\right)$$

Solution Steps

Multiply and combine like terms.

$$-a^{2}-a+2$$

Factor the expression by grouping. First, the expression needs to be rewritten as -a^{2}+pa+qa+2. To find p and q, set up a system to be solved.

$$p+q=-1 pq=-2=-2$$

Since pq is negative, p and q have the opposite signs. Since p+q is negative, the negative number has greater absolute value than the positive. The only such pair is the system solution.

$$p=1 q=-2$$

Rewrite -a^{2}-a+2 as \left(-a^{2}+a\right)+\left(-2a+2\right).

$$\left(-a^{2}+a\right)+\left(-2a+2\right)$$

Factor out a in the first and 2 in the second group.

$$a\left(-a+1\right)+2\left(-a+1\right)$$

Factor out common term -a+1 by using distributive property.

$$\left(-a+1\right)\left(a+2\right)$$

Evaluate

$$\left(1-a\right)\left(a+2\right)$$

Solution Steps

Multiply a and a to get a^{2}.

$$2-a-a^{2}$$