4 to 7 = 4/7
5/8 is not.
12/20 = 6/10 = 3/5 . It is not equivalent.
8:14 = 4 : 7 . It is equivalent
5 to 10 = 1 to 2. It is not.
16/28 = 8/14 = 4/7. It is equivalent.
9 to 16 = 9 to 16. It is not equivalent.
So only 8:14 and 16/28 are equivalent to 4 to 7.
Just set up an equation comparing the two ratios and solve for the length, in this case x.
(10/19)=(6/x)
19/10=x/6
114/10=x
Answer= 11.4 feet for the length of the flower
So, this question is basically asking us "If we had an x instead of a 2, would this be true?" We can try and see what we get:

So, if we want to show this we have to change the numerator or denominator in such a way that we can cancel some common factors. Notice that 
If we replace the factored numerator with the original one, we get:

Since we have an equality, this relation is proved.
X² + 6x -12 = 0
x = <u>-(6) +/- √((6)² - 4(1)(-12))</u>
2(1)
x = <u>-6 +/- √(36 + 48)</u>
2
x = <u>-6 +/- √(84)
</u> 2<u>
</u>x = <u>-6 +/- 2√(21)
</u> 2<u>
</u>x = -3 <u>+</u> √(21)
x = -3 + √(21) x = -3 - √(21)