Look at this from comments then you will find your answer, you’ll see why. y = 2 x ; − 1 y = 5 x − 7
Rewrite equations: y = 2 x ; − y = 5 x − 7
Step: Solve y = 2 x for y: y = 2 x
Step: Substitute 2 x for y in − y = 5 x − 7 : − y = 5 x − 7 − 2 x = 5 x − 7 − 2 x + − 5 x = 5 x − 7 + − 5 x (Add -5x to both sides) − 7 x = − 7 − 7 x − 7 = − 7 − 7 (Divide both sides by -7) x = 1
Step: Substitute 1 for x in y = 2 x : y = 2 x y = ( 2 ) ( 1 ) y = 2 (Simplify both sides of the equation)