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# help

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Farra subtracted 5 from a number and then divided by 4. Next, he subtracted 4 from the original number and then divided by 5. He got the same final answer both times. What was the original number?

Jun 11, 2020

#1
+549
+2

Set $$x$$ as the original number.

Write out equations:

$$\frac {x-5} {4} = \frac {x-4} {5}$$

Cross-multiply:

$$(x-5)5=(x-4)4$$

Simplify to...

$$5x-25=4x-16$$

Solve the equation by subtracting $$4x$$ from both sides:

$$x-25=-16$$

Then add $$25$$ on both sides:

$$x=-16+25=9$$

So the final answer would be $$x=9$$

Jun 11, 2020
#2
+1128
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we would make the equation (x-5)/4=(x-4)/5 and simplify it into 5x-25=4x-16 when we multiply both sides by 20 and subtract 4x from both sides to get x-25=-16 we then add 16 from both side to get x-9=0 and then we finnaly add 9 to both sides to get x=9

Jun 11, 2020