Question

Which ordered pair (m, n) is a solution to the given system of linear equations?

6m-5n= 14
2m+2n= -10

a) (-4,-1)
b) (-31/11,-24/110
c) (-1,-4)
d) (11,-16)

ANSWER: NOT B

Answer 1

Option C

Explanation:

given two equations

6m-5n= 14 ... i

2m+2n= -10 ...ii

We can solve this by elimination.

For elimination consider the coefficients of m.

They are 6 and 2, with LCD 6

You multiply 2nd equation by 3 to have

6m+6n =-30 ... iii and

6m-5n = 14 ... i

Subtract i from iii

11n = -44

Divide by 11 to get n

n = -4

Substitute in I equation

6m-5(-4) =14

6m +20 = 14

subtract 20

6m =14-20 =-6

divide by 6

m =-1

Hence answer is m=-1 and n=-4

(-1,-4)

Option C is the answer.