Question

18. Solve x+y = 5 2x - y =7.​

Answer 1

Step-by-step explanation:

= 7

Solve by Substitution :

// Solve equation [1] for the variable y

[1] y = -x + 5

// Plug this in for variable y in equation [2]

[2] 2x - (-x +5) = 7

[2] 3x = 12

// Solve equation [2] for the variable x

[2] 3x = 12

[2] x = 4

// By now we know this much :

x = 4

y = -x+5

// Use the x value to solve for y

y = -(4)+5 = 1

Solution :

{x,y} = {4,1}