Solving the elimination method what is 3x-y=9 2x-y=7

x = 2 , y = -3

Step-by-step explanation by elimination:

Solve the following system:

{3 x - y = 9 | (equation 1)

2 x - y = 7 | (equation 2)

Subtract 2/3 × (equation 1) from equation 2:

{3 x - y = 9 | (equation 1)

0 x - y/3 = 1 | (equation 2)

Multiply equation 2 by 3:

{3 x - y = 9 | (equation 1)

0 x - y = 3 | (equation 2)

Multiply equation 2 by -1:

{3 x - y = 9 | (equation 1)

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

Add equation 2 to equation 1:

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

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

Divide equation 1 by 3:

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

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

Collect results:

{x = 2 , y = -3

step-by-step explanation: a reaction is first order. if the initial reactant concentration is 0.0200 m, and 25.0 days later the concentration is 6.25 x 10-4 m, then its half-life is:

just needed some points but try socratic