Answer: 0.75 (choice B)
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Explanation:
One way to set up the equation is to think of it like this
vertical/horizontal = vertical/horizontal
So we could say
(3.5)/(28) = x/6
Cross multiply and solve for x
3.5*6 = 28*x
21 = 28x
x = 21/28
x = (3*7)/(4*7)
x = 3/4 in fraction form
x = 0.75 in decimal form
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Another possible set up equation is
28/6 = (3.5)/x
in this case I divided the horizontal sides together (28 and 6) and the vertical sides divide to form their own separate fraction as well.
Solving that equation should lead you to x = 3/4 = 0.75
Other equations are possible.