Maths Polynomials-4

Question

Find the value of (x+y)² if x² -y² = -12 and y-x=2

Answer 1

factor x² - y² as (x + y)(x - y)

 

if y - x = 2 then multiplying by -1 gives you

 

x - y = -2

 

so x² - y² = (x + y)(-2) and that equals -12

 

(x + y)(-2) = -12

 

(x + y) = 6

 

(x + y)² = 36