Question

3a + 5b - 7 = 0 a - 2b - 4 = 0 Solve the system by the elimination method. Check your work

{(96/11, -5/11)}

{(34/11, -5/11)}

{(32/33, 5/11)}

Answer 1

Answer:Be 34-11, -5/11 because of the substitution method

Explanation:

Answer 2

The answer is (34/11, -5/11).

First, let's rewrite the 2 equations:


`3a + 5b - 7 = 0`

`a - 2b - 4 = 0`
Then let's transform these 2 equations into the form ax+by=c

So that would be:

`3a + 5b = 7 \\ a - 2b = 4`
Now our goal is to isolate one of the variables a or b. Lets pick a since its easier. To do this, multiply equation 2 by -3 so that 3a + -3a=0

`- 3a + 6b = - 12`
Now add both equations together:

`\: \: \: \: 3a + 5b = 7 \\ + - 3a + 6b = - 12 \\ \: \: \: \: 11b = - 5`
Now to isolate b, divide both sides by 11

`b = - (5)/(11)`
Now we know the value of b, its time to solve for a

To do this, you substitute b in any equation to -5/11. In this case, I'll choose equation 2.

`a - 2( - (5)/(11) ) = 4 \\ a + (10)/(11) = 4 \\ a = (34)/(1)`