Question

(d) 7m - 2n= 40;m+n= 10​

Answer 1

7m-2n=40

2m+2n=20

m=60/9= 20/3

Answer 2

Answer:

m=20/3,n=-30

Step-by-step explanation:

7m-2n=40......(1)

m+n=10.........(2)

Multiply eqn. (2) by 2.

2m+2n=20.....(3)

Add eqn. (1) and (2).

7m-2n=40

+2m+2n=20

9m=60

m=60/9

m=20/3

Substituting the value of m=20/3 in eqn.(2)

m+n=10

20/3+n=10

(60+n)/3=10

60+n=10*3

n=30-60

n=-30

Solution:-m=20/3,n=-30

I hope it's correct.