Question

Class - 8
3. Multiply
(c) (a + 5) by (a +4)

It is a algebra Question
Please tell me the answer ​

Answer 1

Answer:

(a+5) × (a+4)

=a(a+4) +5(a+4) {DISTRIBUTIVE PROPERTY}

$= {a}^{2} + 4a + 5a + 20$

$= {a}^{2} +9a + 20$

Answer 2

Answer:

$\rm { a^2 + 9a + 25 }$

Step-by-step explanation:

In order to multiply two binomials, we multiply all the terms of the second binomial by each term of the first binomial.

$\longmapsto \rm { (a +5) \; by \; (a + 4)}$

Step 1 : Putting the sign of multiplication at the place of by.

$\longmapsto \rm { (a +5) \times (a + 4)}$

Step 2 : Using the distributive property of the multiplication under addition or multiplying each term of first binomial with each term of second binomial.

$\longmapsto \rm { a(a + 4) + 5(a + 5) }$

Step 3 : Multiply the monomial with each term of the binomial.

$\longmapsto \rm { a^2 + 4a + 5a + 25 }$

Step 4 : Combine all the like terms.

$\longmapsto \rm { a^2 + 9a + 25 }$

∴ The required answer is $\bf { a^2 + 9a + 25 }$