Question

36a² +84ab +49b² if a =-2 and b= 1 ​

Answer 1

Answer:

(6a- 7b)²

Step-by-step explanation:

STEP

1

:

Equation at the end of step 1

((36 • (a2)) - 84ab) + 72b2

STEP

2

:

Equation at the end of step

2

:

((22•32a2) - 84ab) + 72b2

STEP

3

:

Trying to factor a multi variable polynomial

3.1 Factoring 36a2 - 84ab + 49b2

Try to factor this multi-variable trinomial using trial and error

Found a factorization : (6a - 7b)•(6a - 7b)

Detecting a perfect square :

3.2 36a2 -84ab +49b2 is a perfect square

It factors into (6a-7b)•(6a-7b)

which is another way of writing (6a-7b)2

How to recognize a perfect square trinomial:

• It has three terms

• Two of its terms are perfect squares themselves

• The remaining term is twice the product of the square roots of the other two terms

Final result :

(6a - 7b)2

Answer 2

Answer:

If a =-2 and b= 1 in 36a² +84ab +49b²

Then,

36(2)² + 84 (2×1) + 49(1)²

= ( 36 × 4 ) + (84 × 2) + ( 49 × 1)

= 144+168+49

= 361