Question

4x+y=15,3x+5y=41 solve by substitution and check the solution

Answer 1

{x,y} = {2,7}

Explanation:

// Solve equation [1] for the variable y

[1] y = -4x + 15

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

[2] 3x + 5•(-4x+15) = 41 [2] -17x = -34

// Solve equation [2] for the variable x

[2] 17x = 34 [2] x = 2

// By now we know this much :

x = 2 y = -4x+15

// Use the x value to solve for y

y = -4(2)+15 = 7