Question

Question 1

To expand (7r+5s)2 , you can use the pattern (a+b)2=a2+2ab+b2 .


What are the values of a and b?

Answer 1

Explanation:

`(7r+5s)^2`

use the pattern

`(a+b)^2=a^2+2ab+b^2`

`(7r+5s)^2=(7r+5s)(7r+5s)`

Apply FOIL method to multiply the parenthesis

`(7r+5s)^2=(7r+5s)(7r+5s)`

`(7r+5s)(7r+5s)\\49r^2+35rs+35rs+25s^2\\49r^2+70rs+25s^2`

Compare the expression with
`(a+b)^2=a^2+2ab+b^2`

The value of a=7r and the value of b=5s

Answer :

a=7r , b=5s