Evaluate square roots asap

1. evaluate √x+20 when x=16. (answer in simplified radical form.)
a) 36
b) 24
c) 6
d) 4

2. evaluate √21 - x when x =9. (answer in simplified radical form.)
a) √3
b) 2√3
c) 3
d) 4

3. evaluate √21 - x when x =9. (answer as decimal)
a) 1.73
b) 3.46
c) 3
d) 4

Find the value of a. the diagram is not to scale. a quadrilateral is drawn. the upper and lower sides are parallel. the interior angle in the upper left corner is labeled a degrees. the angle in the upper right corner is labeled 113 degrees. the angle in the lower right corner is labeled b degrees. the angle in the lower left corner is labeled 36 degrees. a. 36 b. 144 c. 54 d. 126

What are the possible rational zeros of [tex]f(x) = x^4+2x^3-3x^2-4x+18[/tex]

The verbal translation for the difference of m and 7 increased by 15