Question

Plzzz help don’t understand

Answer 1

A system of linear equations solved by elimination means that you have to figure out a way to eliminate one of the variables so that you can solve for the other one.

Here, you could multiply both sides of the top equation by 2 to get:

2 * (-9x + 2y) = -1 * 2

-18x + 4y = -2

Now line this up with the bottom equation:

-18x + 4y = -2

18x - 7y = 17

We see that if we add the two equations together, we can get rid of the x variable:

4y + -7y = -2 + 17

-3y = 15

y = -5

If we know y, we can use it to find x:

-9x + 2 * -5 = -1

-9x - 10 = -1

Add 10 to both sides:

-9x = 9

Divide both sides by -9:

x = -1

So, the answer is x = -1 and y = -5

Answer 2

The given system of equation is

$-9x+2y=-1..........(1)\\ \\ 18x-7y=17...........(2)\\ \\ \text{To solve the system of equation by elimination, multiply the first equation by 2 }\\ \text{and thereafter add equation 1 and 2 together we get }\\ \\ -18x+4y=-2\\ 18x-7y=17\\ ------\\ -3y=15\\ ------\\ \\ y=-5\\ \text{Now substitute the value of y in equation 1 we get }\\ \\ -9x-10=-1\\ \\ -9x=-1+10\\ \\ -9x=9\\ \\ x=-1\\ \\ \text{Hence the solution to the given system of equation is }\\ \\ x=-1, y=-5$