133k views
5 votes
7x - y = 10 and 7x + 5y = -6

1 Answer

4 votes
Let's use substitution. First, isolate y in the fist equation:

7x - y = 10
-y = -7x + 10
y = 7x - 10

Now, substitute that into the second equation to find x:

7x + 5(7x - 10) = -6
7x + 35x - 50 = -6
42x - 50 = -6
42x = 44
x = 1.0476

Substitute that into the first equation to find y:

7(1.0476) - y = 10
7.3333 - y = 10
-y = 2.6667
y = -2.6667

Lastly, substitute both values into both original equations to check work:

7(1.0476) - (-2.6667) = 10 --> 7.3332 + 2.6667 = 10 <--This is correct
7(1.0476) + 5(-2.6667) = -6 --> 7.3332 - 13.3335 = -6 <--This is correct

Answer:
x = 1.0476
y = -2.6667

Hope this helps.
User Petr Syrov
by
8.1k points

No related questions found

Welcome to QAmmunity.org, where you can ask questions and receive answers from other members of our community.