y=-3x+87 y=6x+17

Question

I need to find a solution to this system. I have been stuck on this type of problem for a while. If someone could explain it in a way a 14-year-old who hates and struggles with math could understand, that would be amazing. Any videos I found were too confusing. I've been out of class due to surgery, otherwise, I wouldn't have to ask. I got x=86/3 and x=-8/3 somehow and I don't understand how I got this or how to solve it correctly.

Answer 1

-3x+87= 6x +17

9x= 70

x=70/9= 7 7/9 = 7.777...

y=-3(70/9)+87= 87-70/3

= 261/3- 70/3 - 191/3

= 79 2/9 = 79.222...

Answer 2

Hi Aislynn T

If your equations are

y = -3x + 87

y = 6x + 17

There are several ways to do the problem, you can set them equal to each other because both represent y

y = y use the substitution

-3x + 87 = 6x + 17

You can add 3x to both sides of the equation

-3x + 3x + 87 = 6x + 3x + 17

3x cancels out on one side and you are left with

87 = 9x + 17

Next subtract 17 from both sides of the equation

87 - 17 = 9x + 17 - 17

17 cancels out on one side

70 = 9x

Divide both sides by 9

70/9 = x

Now plug x into to both equations to find y, you should get the same value for y from each equation

y = -3(70/9) + 87 = 191/3

y = 6(70/9) + 17 = 191/3

Another option would be to move variables to one side of your equations and use elimination

y = -3x + 87 becomes

y+3x = 87

y = 6x + 17 becomes

6 - 6x = 17 you would have two equations in two unknowns to work with

y + 3x = 87

y - 6x = 17

Answer 3

these y=m₁x+b_1,,,,,,which is line y intercept b₁ slope m₁

with (x,y) solution same as y=m₂x+b_2,,,, which is line y intercept b₂ slope m₂

is where two lines intersect. Raymond provides proper (x,y) coordinates.

Answer 4

Hi, if you like we can setup a session to work with your child on systems of equations.