Question

mutiply the following by algebraic expression : 2a - 8b + 7 by 4a - 3b + 5. step by step​

Answer 1

Answer:

• The answer is ↦ 8a² - 38ab + 38a + 24b² - 61b + 35.

Step-by-step explanation:

$\bf{Q)}\;\sf{(2a-8b+7)\times(4a-3b+5)}$

Solution:

By horizontal method:

$\sf{\longmapsto2a(4a-3b+5)-8b(4a-3b+5)+7(4a-3b+5)}$

Opening the brackets,

$\sf{\longmapsto8a^2-6ab+10a-32ab+24b^2-40b+28a-21b+35}$

Arranging the variables,

$\sf{\longmapsto8a^2+24b^2+(-6ab-32ab)+(10a+28a)+(-40b-21b)+35}$

Opening the brackets,

$\sf{\longmapsto8a^2+24b^2-38ab+38a-61b+35}$

By column method:

$\sf{2a-8b+7}\\\underline{\sf{4a-3b+5\;\;\;\;\;\;\;\;\;\;\;}}\\\sf{8a^2-32ab+28a}\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\bf{multiplying\;by\;4a} \\\sf{\;\;\;\;\;\;\;\;-6ab+\;\;0\;\;+24b^2-21b}\;\;\;\;\;\;\;\;\;\;\;\;\;\bf{multiplying\;by-3b}\\\underline{\sf{\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;10a+\;\;0\;\;-40b+35}\;\;}\;\;\;\;\;\bf{multiplying\;by\;5}\\\underline{\sf{8a^2-38ab+38a+24b^2-61b+35}}$

Hence,

• (2a - 8b + 7) × (4a - 3b + 5) = 8a² - 38ab + 38a + 24b² - 61b + 35