Question

If 3m - 5m = -1 and 2m = n-3, find the value of (3m+5n) and (m+2n).

• A. -1, 2
• B. -1, -2
• C. 11, 4
• D. -11, -4

Answer 1

The correct option is D

-11, -4

3m-5n=-1 ..............(i)

2m=n-3 ................(ii)

Multiplying (i) by 2 and (ii) by 3 and subtracting (ii) from (i) -

6m - 10n - (6m - 3n) = -2 + 9

$\Rightarrow$ -7n=7 $\Rightarrow$ n=-1

Substituting value of n (ii), we get

2m-(-1)=-3 $\Rightarrow$ 2m+1 = -3

$\Rightarrow$ 2m=-4 $\Rightarrow$ m=-2

(3m+5n) =3(-2)+5(-1)

=-6-5=-11

and (m+2n)=-2+2(-1)

=-2-2=-4