Question

If x + y = 12 and xy= 27, find the value

of x

3 + y

3​

Answer 1

Step-by-step explanation:

$x + y = 12 \\ xy = 27 \\ x = y - 12 \\ (y - 12)y = 27 \\ y {}^{2} - 12y = 27 \\ y {}^{2} - y = 27 \\ y {}^{2} - y - 27 = 0 \: (splitting \: the \: middle \: term) \\ or \\ use \: formula \\ - b \times + or - \sqrt{b { - 4ac \div 2a}^{2} }$

no 2a^2

only 2a