Question

n/2-3n/4+5n/6=21 solve​

Answer 1

Answer:

n=36

step - by - step explanation

Answer 2

Answer:

$\frac{n}{2} - \frac{3n}{4} + \frac{5n}{6} = 21$

We've to take L.C.M of 2,4,6

here

L.C.M=12(2×2×3)

$\frac{n}{2} \times \frac{6}{6} = \frac{6n}{12} \\ \\ \frac{3n}{4} \times \frac{3}{3} = \frac{9n}{12} \\ \\ \frac{5n}{6} \times \frac{2}{2} = \frac{10n}{12} \\ \\ \frac{6n}{12} - \frac{9n}{12} + \frac{10n}{12} \\ \\ \frac{6n - 9n + 10n}{12} \\ \\ = \frac{7n}{12}$

and now let's find n,as we've got the values

$\frac{7n}{12} = 21 \\ 7n = 21 \times 12 \\ 7n = 252 \\ n = \frac{252}{7} \\ n = 36$

therefore the value of n=36

Let's check whether it's correct or not

$\frac{36}{2} - \frac{3 \times 36}{4} + \frac{5 \times 36}{6} = 21 \\ 18 - \frac{108}{4} + \frac{180}{6} = 21 \\ 18 - 27 + 30 = 21 \\ 21 = 21$

L.H.S=R.H.S

hence verified

hope it helps