The correct option would be C
Answer:
the answer is 30
Step-by-step explanation:
Multiply the numerator by the numerator (top number).
Multiply the denominator by the denominator (bottom number).
So 3 x 6 = 18
And 5 x 7 = 35
= 18/35
The first is a. you can rewrite it

the second is d. the only common factor between 20 and 40 that can be taken out is the 4 which becomes a 2, but inside the square roots there is still a 5 and 10, which cannot be combined
the third is c.

the fourth is d.
add 3 to both sides

then square both sides

then divide both sides by 2, x=50