Question

Solve the following pair of simultaneous equation using elimination method.

3x_2y=7
X+2y= _3
​

Answer 1

x = 1 and y = −2

Explanation:

Rewrite equations:

x + 2y = −3

3x − 2y = 7

Step 1: Solve x+2y=−3 for x:

x + 2y = −3

x + 2y + −2y = −3 + −2y (Add -2y to both sides)

x = −2y − 3

Step 2: Substitute −2y − 3 for x in 3x − 2y = 7:

3x − 2y = 7

3(−2y − 3) − 2y = 7

−8y − 9 = 7 (Simplify both sides of the equation)

−8y − 9 + 9 = 7 + 9 (Add 9 to both sides)

−8y = 16

−8y/−8 = 16/−8 (Divide both sides by -8)

y = −2

Step 3: Substitute −2 for y in x = −2y − 3:

x = −2y − 3

x = (−2)(−2) − 3

x = 1 (Simplify both sides of the equation)