Question

(y-1)(y+2)+(y+1)(y-2)​

Answer 1

$(y - 1)(y + 2) + (y + 1)(y - 2) = y {}^{2} + 2y - y - 2 + y {}^{2} - 2y + y - 2 = y { }^{2} + y {}^{2} - 4 = 2y {}^{2} - 4$

Answer 2

To simplify the given expression, you can use the distributive property to expand the terms and then combine like terms. Let's do that step by step:

1. Expand the terms: (y - 1)(y + 2) + (y + 1)(y - 2)

Using the distributive property, we get: (y * y) + (y * 2) + (-1 * y) + (-1 * 2) + (y * y) + (y * -2) + (1 * y) + (1 * -2)

2. Combine like terms: y^2 + 2y - y - 2 + y^2 - 2y + y - 2

3. Simplify further: Combine the like terms: (2y - y) and (y - 2y) y^2 + y - 4

So, the simplified form of the expression (y - 1)(y + 2) + (y + 1)(y - 2) is y^2 + y - 4.