Question

Find a polynomial, which if substituted for M will make the equation an identity: M + (5x2 –2xy) = 6x2 +9xy–y2

Answer 1

M=x^2+11xy-y^2

Explanation:

To find M you have to subtract.

6x^2+8xy-y^2-(5x^2-2xy)

6x^2+9xy-y^2-5x^2+2xy

6x^2+11xy-y^2-5x^2

x^2+11xy-y^2

Answer 2

Answer: you just solve for M

M = x^2 + 11xy – y^2

Explanation:

M + (5x^2 –2xy) = 6x^2 +9xy–y^2

M = 6x^2–5x^2 + 9xy+2xy – y^2

M = x^2 + 11xy – y^2

Check:

x^2 + 11xy – y^2 + 5x^2 – 2xy

6x^2 + 9xy – y^2