11. What is the sum of -3x²y, 5x²y and 7x²y?
a. -15x²y
b. -9x²y
c.9x²y
d. 15x²y
12. Which of the following is a linear equation with one variable?
a. 2x + y = -7
b. -5 + y = z
c. x² – 5x = 4
d. 4x - 8 = 12
13. Simplify (2x²y)(-4x³y⁴)
a. -8x⁵y⁵
b. -8x5y4
c.8x⁵y⁵
d. 8x⁶y⁴
14. Simplify (3a²b2c)2
a. 6a³b²c
b. 9a⁵b⁴c³
c.9a⁶b⁴c²
d. 6a⁶b4c²
15. What is (x - 4)(x + 4)?
a. x²-16
b. x² - 8x - 16
c. x² + 8x - 16
d. x² + 16
16. Find the sum (3x - 5y) + (2x + 7y)
a. 5x - 12y
b. 5x + 12y
c. 5x - 2y
d. 5x + 2y
17. Simplify
-15x⁵y³z⁴
3x2²yz²
a. -5x³y³z²
b. 5x³y³z²
c. -5x³y²z²
d. 5x⁷y⁴z⁶​