117k views
2 votes
Just a quick question!

Solve using substitution.

–3x − 4y = 17
x − y = –1
Help please!

1 Answer

6 votes

Answer:

(-3, -2)

Explanation:

-3x -4y = 17

x -y = -1 Can be rewritten x = y - 1

Substitute y -1 for x into the first equation

-3(y - 1) - 4y = 17 Distribute the -3

-3y + 3 -4y = 17 Combine like terms

-7y + 3 = 17 Subtract 3 from both sides

-7y = 14 Divide both sides by -7

y = -2

Substitute -2 for y in x = y -1 to solve for x

x = -2 -1

x = -3

Check

-3x -4y = 17

-3(-3) - 4(-2) = 17

9 + 8 = 17

17 = 17 checks

x -y = -1

-3 -(-2) = -1

-3 + 2 = -1

-1 = -1 checks

User Fabilous
by
7.7k points