Respuesta :

jcherry99

Answer:

3a^2 + 20a + 34

Step-by-step explanation:

(2a + 5)^2 = 4a^2 + 20a + 25

(a +3)(a - 3) = a^2 - 9

Put these two partial answers together.

4a^2 + 20a + 25 -(a^2 -9 )                 Remove the brackets.

4a^2 + 20a + 25 -  a^2 + 9

4a^2 + 20a + 25 - a^2 + 9

3a^2 + 20a + 34

eunice1234

Answer: 3a² + 20a + 34

Concept:

When doing simplifying expressions, following the PEMDAS method would be easier.

  • Parentheses
  • Exponents
  • Multiplication
  • Division
  • Addition
  • Subtraction

When expanding parentheses, following the FOIL method would be easier.

  • First
  • Outer
  • Inner Last

Solve:

Given expression

(2a + 5)² - (a + 3) (a - 3)

Simplify exponenets

= (2a + 5) (2a + 5) - (a + 3) (a - 3)

Expand parentheses

= 4a² + 10a + 10a + 25 - (a² - 3a + 3a - 9)

= 4a² + 10a + 10a + 25 - a² + 3a - 3a + 9

Combine like terms

= 4a² - a² + 10a + 10a + 3a - 3a + 25 + 9

= 3a² + 20a + 34

Hope this helps!! :)

Please let me know if you have any questions

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