Question

find the value of x^2 + y^2, if x + y = 15 and xy = 10​

Answer 1

Answer:

205

Step-by-step explanation:

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

(x+y)^2=x^2+y^2+2xy

(15)^2=x^2+y^2+2(10)

225=x^2+y^2+20

225-20=x^2+y^2

205=x^2+y^2

x^2+y^2=205

Answer 2

Answer:

205

Step-by-step explanation:

(x+y)

${(x + y)}^{2} = {x}^{2} + {y}^{2} + 2xy$

sub 2xy from both side we can get the answer

so

${(x + y)}^{2} - 2xy = {x}^{2} + {y}^{2}$

${(x + y)}^{2} - 2xy = {15}^{2} - 2 \times 10$

•°• 225-20

=205

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