Katherine B. answered • 04/07/21
Flexible Tutor in a Wide Range of Subjects
In order to subtract the second equation, the first step is to make the second equation negative. I think 3.0 is a typo and you meant to write 3x, so I will change that.
- 3x + 2y = 7
-(-3x – 2y = 4)
This changes the second equation to 3x + 2y = -4
Because you started with a negative, it is now a positive and you'd be doing addition. The next step is to combine like terms.
-3x + 3x + 2y + 2y = 7-4
The negative 3x and positive 3x cancel each other out, so you're left with
2y + 2y = 7 - 4
4y = 3
If you wanted to solve for y, divide both sides of the equation by 4, which leaves you with
4y/4 = 3/4
y= 3/4
Just in case that was supposed to be a 3.0 in your original post, here's the solution if there was no typo
- 3x + 2y = 7
-(-3.0 – 2y = 4)
-3x + 2y + 3 + 2y = 7-4
-3x + 4y + 3 = 3
Subtract 3 from both sides of the equation to isolate your variables
-3x + 4y + 3 - 3 = 3 - 3
Your final answer is
-3x + 4y = 0
