The solution to the system equations

Mathematics

1 answer:

katovenus [111]3 years ago

3 0

Let's solve this system of equations through substitution.

We have these two equations.

-7x-2y=14

6x+6y=18

Now let divide the second equation by 6.

6x+6y=18 ----> x+y=3

Next, let us move y to the right side of the equation.

x+y=3 -------> x=3-y (x equals 3-y)

Because we found out that what x is in terms of y, we can input that in for every instance of x in this equation below.

-7x-2y=14 becomes -7(3-y)-2y=14 (Why? Because x equals 3-y!)

We have a one variable equation now and can solve for y.

-7(3-y)-2y=14

-21+7y-2y=14

5y=35

y=7

Plug in 7 for y in any equation to find x.

x+y=3

x+7=3

x=-4

answer: x=-4, y=7

You might be interested in

Solving systems equations by elimination

pishuonlain [190]

I won't answer them all for you (don't want to cheat - need to learn something).
But for the first one given:

<span>-2x-9y=-25
-4x-9y=-23

you set up either x or y (which ever one you want to eliminate) so that one of them cancels.
So this one is easy - you just have to multiply an entire row by negative (doesn't matter which one) - so that the y's will be + and -

Since they're both 9 and they're subracting NOW - you can eliminate the y value. Now add/subtract the x's. So it'd be -2 or 2 depending on how you eliminated y. Then add the number outside of the = sign. Now just solve for x. After that plug in whatever you got for x into both of the rows. Then find the y value.

Hopefully this wasn't confusing -- reply if it is and I will try to simplify. I can give you contact if you need help with the rest

Good luck!</span>

3 0

3 years ago

What is the expression 3(x+6)+21+14x in simplest combined form

kolezko [41]

Answer:

Step-by-step explanation:

5 0

3 years ago

The population of a town can be modeled by the regression equation y=18,000(1.04^x). Which is the best prediction for the popula

ANEK [815]

X= 30
y=18,000(1.04³⁰)=18,000(3.24339751)≈58381

answer: B)58,381

4 0