The whole number such that twice of its square added to itself gives 10

Expansion of (x + 3y)(x - y) gives

A. x² + 2xy - 3y²

B. x + 3y - 2xy

C. -2y + 3x

D. 3y - 42x

9a² - 4 gives

A. (3a + 2)(3a - 2)

B. 9a + 12

C. (4a + 13)(4a - 13)

D. 54a - 32

Factorize x² + 8x + 12

A. (x + 2)(x + 6)

B. (x + 3)(x + 4)

C. 3x + 12

D. 3x - 12

If x=3 is solution of x² + kx + 15, the value of k is

A. k = -8,x = 5

B. k = 8, x = 3

C. k = 6, x = 5

D. None of above

Expansion of 2x(x + 2y) + 3x(2x - 3y) yields

A. 8x² - 5xy

B. 8x - 5y

C. 3y - 2y

D. none of above