Question

Find the value of x³ - 8y³ - 36xy - 216 , when x = 2y + 6.???​

Answer 1

ɢɪᴠᴇɴ:

• x³ - 8y³ - 36xy - 216
• when (x = 2y + 6)

ᴛᴏ ғɪɴᴅ:

• Find the values of x ?

Formula Used:

a³ + b³ + c³ - 3abc

sᴏʟᴜᴛɪᴏɴ:

➨ x³ - 8y³ - 36xy - 216

➨x³ + (-8y³) + (-216) - 36xy

➨x³ + (-2y)³ + (-6)³ - 3 × x × (-2y) × (-6)

➨a³ + b³ + c³ - 3abc

We can replace a , b and c with x , -2y and (-6).

we get;

(a + b + c) (a² + b² + c² - ab - bc - ca)

➨(x - 2y - 6) (x² + 4y + 36 + 2xy - 12y + 6x )

➨0 × (x² + 4y² + 36 + 2xy - 12y + 6x) = 0

Therefore:

x³ - 8y³ - 36xy - 216 = 0 is the Final value.