Question

Factor the expression over the complex numbers.


y^2+49

Answer 1

`\text{Use}\\\\a^2-b^2=(a-b)(a+b)\\\\i=√(-1)\to i^2=-1\\---------------------\\\\y^2+49=y^2+7^2=y^2-(-1)(7^2)=y^2-(i^2)(7^2)=y^2-(7i)^2\\\\\boxed{y^2+49=(y-7i)(y+7i)}`