18. An expression is a polynomial if
A. The variable is inside the radical sign.
B. There is a variable in the denominator
C. The exponent of the variable is negative.
D. Each term is constant, a variable or a product of a constant and variable
19. What is the degree of the polynomial 3x2y3 – xy2 + 2x3y?
A. 5
B. 4
C. 3
D. 11
20. If x = 2 and y = 1, then x2y + y2 is equal to ?
A.6
B. 7
C. 5
0.8
21. What is the difference if 10x2 - x - 3 is subtracted from 21x2 – 3x + 1?
A. 11x2 - 2x + 4 B. 11x2 + 2x - 4 C. 31x2 - 4x + 4 D. 11x
22. What must be added to -18xy? to get 45xy??
A. 27xy?
B.-27xy?
C. 63xy?
D. -6
23. Let y = 2x + 9. What is y when x = 3?
A. 16
B. 15
C. 14
D. 10
24. Subtracting 5k3 - 2k + 4 from 13k3 + 4K - 10 yields
A
18k3 - 6k + 4
B. 8k3 + 6k + 4 C. 8k? + 6k - 14 D.​