Simplify the expression \$ (4y^2) + (7y^2) \$.

A) \$11 y^3\$

B) \$15 y^2\$

C) \$15 y^3\$

D) \$11 y^2\$

Simplify the expression \$ 3x + 5x^3 + 9x + 6x^2 - 9x^3 \$.

A) \$4x^3 + 9x^2 + 3x\$

B) \$-4x^3 + 6x^2 + 12x\$

C) \$-4x^3 + 8x^2 + 12x\$

D) \$4x^3 + 6x^2 + 9x\$

Simplify the expression \$ (3x^2) + (2y) - (4x^2) \$.

A) \$ (-x^2) + 3y \$

B) \$ (x^2) + 2y \$

C) \$ (-x^2) + 2y \$

D) \$ (x^2) + 3y \$

Simplify the expression \$ (8xy) + (3yx) \$.

A) 11xy

B) 12xy

C) 5xy

D) - 5xy

Simplify the expression:

\$ 5 + y^5 + 3y^2 -9y^5 + y^3 -7 -y^2\$

A) \$-8y^5 + 4y^2 + y^3 - 2\$

B) \$6y^5 + 2y^2 + y^3 - 9\$

C) \$8y^5 + 5y^2 + y^3 - 2\$

D) \$-8y^5 + 2y^2 + y^3 - 2\$