Question

I don't know what I'm doing wrong, this is solving rational equation using cross products. i don't get how I'm supposed to factor that.

Answer 1

Let's check your solution by starting from the top:

Given the expression:

`\text{ }(15)/(a^2-1)\text{ = }\frac{5}{2a\text{ - 2}}`

Let's simplify. We get,

`\text{ }(15)/(a^2-1)\text{ = }\frac{5}{2a\text{ - 2}}`
`\text{ }(15)(2a\text{ -2) = }(5)(a^2\text{ -1)}`
`\text{ 30a - 30 = 5a}^2\text{ - 5}`
`\text{5a}^2\text{ - 5 - 30a + 30 = 0}`
`\text{5a}^2\text{ - 30a + 25 = 0}`
`(\text{5a}^2\text{ - 30a + 25 = 0)(}(1)/(5))`
`\text{ a}^2\text{ - 6a + 5 = 0}`
`\text{ (a - 1)(a - 5) = 0}`