Question

find the simultaneous solution
m=n/3
5m/2-5n=20

Answer 1

The first thing I would do is multiply both sides of 5m/2-5n=20 by 2

This is so you can clear out the fraction

Answer 2

5m/2-5n=20

2*(5m/2-5n)=2*20

2*(5m/2) + 2*(-5n) = 2*20

5m - 10n = 40


making sense so far?

Answer 3

yup

Answer 4

m=n/3 turns into 3m = n when you multiply both sides by 3

Answer 5

so n = 3m

Answer 6

5m - 10n = 40

5m - 10(3m) = 40 ... replace n with 3m (works because n = 3m)

5m - 30m = 40

what do you get when you solve for m?

Answer 7

so u divide 40 by 25

Answer 8

-25

Answer 9

because 5-30 = -25

Answer 10

so then it would be -1.6

Answer 11

correct, which is the fraction m = -8/5

Answer 12

once you know the value of m, you can find the value of n

Answer 13

use n = 3m and replace m with -1.6 or -8/5 and evaluate

Answer 14

how would it be -8/5

Answer 15

well using a calculator, you get -8/5 = -1.6

or you can think of -1.6 as -16/10 and reduce that to get -8/5

Answer 16

oh mmk thank u so much

Answer 17

-1.6/1 = -16/10 ... multiply top and bottom by 10 to move the decimal over

Answer 18

np