Question

How to solve x=2y and 6y-3x=18 by using subsitution

Answer 1

This system of equations has no solutions

Explanation:

in the linear equations, if the variable is disappeared, and

• The two sides of the equation are equal, then the equation has infinitely many solutions

• The two sides of the equation are not equal, then the equation has no solutions

Let us solve the question

∵ x = 2y ⇒ (1)

∵ 6y - 3x = 18 ⇒ (2)

→ Substitute x in equation (2) by the value of x in equation (1)

∵ 6y - 3(2y) = 18

∴ 6y - 6y = 18

∴ 0 = 18

→ 0 can not equal 18

∴ Left hand side ≠ Right hand side

→ From the 2nd note above

∴ This system of equations has no solutions