Question

2x+9y=27 x-3y=-24 It’s substitution

Answer 1

Answer:

x = -9, y = 5

Step-by-step explanation:

Since we need to solve this system of linear equations by substitution, let's transform the second equation into the form, x = ay + b. We start off with x - 3y = -24, subtract 3y from both sides, and we get x = 3y - 24. Then, substitute the expression 3y - 24 for y in 2x + 9y = 27.

2(3y - 24) + 9y = 27    Substitute 3y - 24 for x.  

6y - 48 + 9y = 27        Distribute 2.

15y = 75                      Add & subtract to combine the like terms.

y = 5                            Divide by 15.

Now that we have the value of y, we can find x by substituting 5 for y in any of the equations. Let's use 2x + 9y = 27 for example.

2x + 9(5) = 27             Substitute 5 for y.

2x + 45 = 27               Multiply.

2x = -18                       Subtract.

x = -9                          Divide by 2.