Question

Using Identity,Find the value of the following:
25x²+60xy+36y²,if x=-1, y=2
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Answer 1

Firstly lets simplify the expression through the below identity

$\boxed{\sf (a+b)^2=a^2+2ab+b^2}$

$\\ \sf\longmapsto 25x^2+60x^2+36y^2$

$\\ \sf\longmapsto (5x^2)+2(5x)(6y)+(6y)^2$

$\\ \sf\longmapsto (5x+6y)^2$

• .x=-1
• y=2

put the values

$\\ \sf\longmapsto (5(-1)+6(2))^2$

$\\ \sf\longmapsto (-5+12)^2$

$\\ \sf\longmapsto (-5)^2+2(-5)(12)+12^2$

$\\ \sf\longmapsto 25-120+144$

$\\ \sf\longmapsto 25+24$

$\\ \sf\longmapsto 49$

Answer 2

Step-by-step explanation:

25x²+60xy+36y²,if x=-1, y=2