Question

6 x + y =1

y = 2 x -3

Select one:
A. (1, 4)
B. (1/2 , -2)
C. (2, -2)
D. (4, 2)

Answer 1

x = 1/2 , y = -2 thus the answer is B.)

Explanation:

Solve the following system:

{6 x + y = 1 | (equation 1)

y = 2 x - 3 | (equation 2)

Express the system in standard form:

{6 x + y = 1 | (equation 1)

-(2 x) + y = -3 | (equation 2)

Add 1/3 × (equation 1) to equation 2:

{6 x + y = 1 | (equation 1)

0 x+(4 y)/3 = -8/3 | (equation 2)

Multiply equation 2 by 3/4:

{6 x + y = 1 | (equation 1)

0 x+y = -2 | (equation 2)

Subtract equation 2 from equation 1:

{6 x+0 y = 3 | (equation 1)

0 x+y = -2 | (equation 2)

Divide equation 1 by 6:

{x+0 y = 1/2 | (equation 1)

0 x+y = -2 | (equation 2)

Collect results:

Answer: {x = 1/2 , y = -2