Simplify (5z - 12y)2 + (12z + 5y)2 - 144z2
Show answer & explanation
Correct answer: C
Explanation
The correct answer is option 3 i.e. 25z2 + 169y2.
(a - b)2 = a2 - 2ab + b2
(a + b)2 = a2 + 2ab + b2
Now, (5z - 12y)2 + (12z + 5y)2 - 144z2
= (25z2 - 120zy + 144y2) + (144z2 + 120zy + 25y2) - 144z2
= 25z2 - 120zy + 144y2 + 144z2 + 120zy + 25y2 - 144z2
= 25z2 + 169y2
Therefore, the required value is 25z2 + 169y2.