Question

Question 1

Answer 1

Step-by-step 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