Answer:
Step-by-step explanation:
You have to use the discriminant for this. If the quadratic is 
, then
a = -4, b = -3, and c = 7. The formula for finding the discriminant is
which comes from the quadratic formula, but without the square root sign. Filling in:
which simplifies down to
D = 9 + 112 so
D = 121. This is a perfect square, so the solutions will be 2 real. Just so you know, you will NEVER have a solution like the one offered in the third choice down. If you have one imaginary root, you will ALWAYS have a second by the conjugate rule.
The rule of geometric sequence is ⇒⇒⇒ a * r^(n-1)
Where a is the first term and r is the common ratio
for the given sequence √5 , √10 , 2√5 , .......
a = √5
r = √10 / √5 = √2
The ninth term = √5 * (√2)^(9-1) = √5 * (√2)⁸ = 16 √5
the correct answer is the third option 16√5
1/3 x - 1/2 = 18 1/2
1/3 x = 19 (add 1/2 on the right side to 18 1/2)
x = 57 (multiply the reciprocal of 1/3 and that will be 3/1 or 3 to 19 to get x by itself)
So, the answer is x = 57 (d. 57)
