1. Square of a Trinomial
By: Mr.Jay Mar Bolajo

2. ( x + y + z) = x2 + y2 + z2 + 2xy + 2xz + 2yz
Square the first term
Square the second term
Square the third term
Twice the product of 1st and 2nd terms
Twice the product of 1st and 3rd terms
Twice the product of 2nd and 3rd terms

3. Examples
(2a+2b+2c)2 = (2a)2 + (2b)2 + (2c)2 + 2(2a)(2b) + 2(2a)(2c) + 2(2b)(2c) = 4a2 + 4b2 + 4c2 + 8ab + 8ac + 8bc

4. Examples
(x + 2y – 3)2 = x2 + (2y)2 + (-3)2 + 2(x)(2y) + 2(x)(-3) + 2(2y)(-3) = x2 + 4y xy – 6x – 12y

5. Try this!
(3m – n + 1)2

6. Answer
9m2 + n2 + 1 – 6mn + 6m – 2n

7. Try this!
Expand: ( x + 3y + 4z)2

8. Answer
x2 + 9y2 + 16z2 + 6xy + 6xz + 24 yz

9. Try this!
Find the expansion of ( 4r – 5s – 2t)2

10. Answer
16r2 + 25s2 + 4t2 - 40rs – 16rt + 20st

11. Skill Practice: Find the product of the following. ( a – b + c )2
(2x + 3y + 4)2
(3x – 2y + 4)2
(5x + 3y – 2)2
(x – 2y + 5)2

12. Answers a2 + b2 + c2 -2ab + 2ac -2bc 4x2 + 9y2 + 16 + 12xy + 16x + 24y

13. Homework (a + 2b – c)2 (5x – 2y + 1)2 (8x – 2y + 3)2 (3x2 – 2y2 + 1)2
Find the expanded form of the following.
(a + 2b – c)2
(5x – 2y + 1)2
(8x – 2y + 3)2
(3x2 – 2y2 + 1)2
( x3 + y2 + 4)2