3:2 because 18/12 and 30/20 both reduce to 3/2
So use pythagorean theorem
a^2+b^2=c^2
a=base
b=height
c=legnth of ladder
a=2
b=c-0.5
subsitute
2^2+(c-0.5)^2=c^2
4+c^2-c+0.25=c^2
add like terms
c^2-c+4.25=c^2
subtract c^2 from both sides
-c+4.25=0
add c to both sides
4.25=c
the legnth of the ladder is 4.25 m
To answer the question, I assume that the given percentage is in terms of volume. The amount of bleach in gallons is the product of the amount of solution x and the decimal equivalent of the percentage. That would give answer equal to 0.70x. The answer is the second choice.
1. Given
2. Combine like terms
3. Subtraction POE (Property of Equality)