Simplify (2z - 5y)2 + (5z + 2y)2 - 25z2.
Show answer & explanation
Correct answer: C
Explanation
The correct answer is option 3 i.e. 29y2 + 4z2.
We know,
(a + b)2 = a2 + b2 + 2ab
(a - b)2 = a2 + b2 - 2ab
According to the question;
⇒ (2z - 5y)2 + (5z + 2y)2 - 25z2
⇒ 4z2 + 25y2 - 20yz + 25z2 + 4y2 + 20yz - 25z2
⇒ 29y2 + 4z2