If 3x - 7y = 10 and xy = -1, find the value of 9x2 + 49y2

Here, we will use (a+b)2 = a2 + b2 + 2ab

Q11 of 84 Page 5

If 3x - 7y = 10 and xy = -1, find the value of 9x² + 49y²

Here, we will use (a+b)² = a² + b² + 2ab

If 9x² +25y² = 181 and xy = -6, find the value of 3x +5y

If 2x +3y = 8 and xy = 2, find the value of 4x² +9y²

Simplify each of the following products:

(i)

(ii)

(iii) -x² + 2x

(iv) (x² + x – 2) (x² - x + 2)

(v) (x³ - 3x² – x) (x² - 3x + 1)

(vi) (2x⁴ - 4x² + 1) (2x⁴ - 4x² - 1)

Prove that a²+ b²+c²–ab–bc–ca is always non-negative for all values of a, b and c.