How do you solve 42/56=6/f4256=6f?

1 Answer
May 1, 2017

f=8f=8

Explanation:

color(blue)("Method 1")Method 1

You spot that 7 is a factor of both 42 and 56. You also spot that
42-:7=642÷7=6

So by the laws that govern ratio we have:

(42-:7)/(56-:7)=6/842÷756÷7=68

Thus f=8f=8
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color(blue)("Method 2")Method 2
You can do this! Turn everything upside down so that the ff in a numerator (on top)

56/42=f/65642=f6

Multiply both sides by 6

56/42xx6=(fxx6)/65642×6=f×66

56/42xx6=(fxx6)/65642×6=f×66

(4xx14)/(3xx14)xx6=fxx6/64×143×14×6=f×66

Note that both 6/6 and 14/1466and1414 are the same as 1

4xx2=f4×2=f

f=8f=8