Question

Solve using the substitution method:
x+3y=10
xy=7

Answer 1

HI JUANITA I DID NOT SEE UR REPLY.....FIND THE LCM OF 6Y^4 AND 18Y^5

Answer 2

x + 3y = 10
x = 10 - 3y
x = 7/y

x = x
10 - 3y = 7/y

y(10-3y) = 7y
10y - 3y^2 = 7y

3y = 3y^2
3y^2 - 3y = 0
3y(y - 1) = 0
y = 0, 1

Answer 3

I typed in that answer but it was incorrect. I need two points that will equal both equations.

Answer 4

Notice, I only solved for y, not x

Answer 5

Clearly that is only values for y

Answer 6

you mean you need one point with two coordinates (x,y)

Answer 7

By the way the point is (1,7)

Answer 8

So would I plug y into the equation to get x?

Answer 9

Yes, correct. We had two values for y we could choose from. Either y = 0 or y = 1 would work. In this case, y = 0 is not a solution because xy = 7 => x*0 = 7 => 0 = 7 is not true

Answer 10

So only y = 1 would work

Answer 11

Ahhh okay! I understand now. Thank you!

Answer 12

I think Luis Rivera posted another solution but I'm convinced that his is not correct.

Answer 13

He has included another point

Answer 14

x + 3y = 10
x = 10 - 3y
x = 7/y

x = x
10 - 3y = 7/y

y(10-3y) = 7
10y - 3y^2 = 7

3y^2 - 10y + 7 = 0
3y^2-3y-7y+7 = 0
3y(y-1)-7(y-1)=0
(y-1)(3y-7)=0
y = 1
y = 3/7

x = 7
x = 3