SOLUTION: the problem is 2x+3y=11 x-4y=0 I cannot figure out what to do with the x in the sescond equation.

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Question 100064This question is from textbook Thinking Mathematically
: the problem is
2x+3y=11
x-4y=0
I cannot figure out what to do with the x in the sescond equation. This question is from textbook Thinking Mathematically

Found 3 solutions by scott8148, edjones, Adam:
Answer by scott8148(6628)   (Show Source):
You can put this solution on YOUR website!
solve for it and then substitute into the first equation

x-4y=0 ... x=4y

2(4y)+3y=11 ... 8y+3y=11 ... y=1

x=4(1) ... x=4

Answer by edjones(8007)   (Show Source):
You can put this solution on YOUR website!
A) 2x+3y=11
B) x-4y=0
.
in B) add 4y to both sides: x=4y
replace x with 4y in A): 8y+3y=11...11y=11...y=1
replace y with 1 in either equation: (I will do B) x-4=0...x=4
Ed

Answer by Adam(64)   (Show Source):
You can put this solution on YOUR website!
This is a system of 2 linear equations with two variables. You can, for instance, express the x from second equation(in terms of y) and substitute it into first equation - thus you'll get linear equation with one variable.Which you can easily solve and substituting answer into any of the original equations get the rest of the solution.
2x+3y=11
x-4y=0 /+4y
x=4y
2x+3(4y)=11
2(4y)+3y=11
8y+3y = 11
11y = 11
y = 1
now we can substitute into any equation
i.e.: 2x+3(1)=11
2x+3 = 11 /-3
2x = 8 /:2
x = 4

after plotting it looks like this: