for the equation y=mx+b, y represents the function, m represents slope, b represents y-intercept, what is x?

Question

Samething with y= ax^2+bx+c
abc are constants, and x is a variable. Is that the same for y=mx + b. How do you find x for y=mx+b?

for the quadratic, to solve for x, make y=0, to solve for y, make x=0. Why isn't this rule the same for a linear equation. Why for a linear equation, you can't sub in 0 for x to solve for y or 0 for y to solve for x, why must you need a set of ordered pairs. If you were given just the equation of y=2x+3, how would you get its set of ordered pairs.

Answer 1

X is just the dependent variable.

For quadratic equations, you cant "solve for X" by plugging in 0 for Y. When you do that, you are solving for X-Intercepts.

The reverse is also true, you plug in 0 for X to solve for Y-Intercepts.

To get the points of a linear equation, just solve for Y with whatever value of X you want.

Answer 2

Consider an example:-
y = 3x + 5
This is the equation of a straight line.
To draw the line, 2 points are required.
Suitable points are (0 , 5) and (4,17)
A straight line may now be drawn thro` these points.
All points on this line then satisfy the equation
y = 3x + 5
x is the horizontal axis
y is the vertical axis.

If y = 20 , 3x + 5 = 20
3x = 15
x = 5 (ie x may be found)

A similar argument applies to :-
y = ax² + bx + c except that in this case we are dealing with a curve as opposed to a straight line.

Hope this helps.

Answer 3

X just represents the variable in the equation.

X represents the input as Y represents the output. Whatever you put in as X, you will get an answer for Y.

In the mx+b formula, X can practically be anything. For example, 2x + 3 is an example of the mx+b formula. Let us make X equal to 2 and your final result will be 7 thus (2,7) is a point on that line.

Answer 4

In the equation y = mx + b the letter m stands for the slope and the letter b is the y intercept, also x and y are the variables.

Answer 5

hey boy,
only ax^2+bx+c = 0 is a quadratic equation
a one variable equation (X) needs just one equation to solve it
a two variable equation (X,Y) does need 2 such equations to solve them
a three variable eqn (X,Y,Z) needs 3 such eqns to solve them
likewise goes on....

EDIT:
remember, anything that exists can be put as a equation
examples:
for 1 variable eqn,
5 apples costs 10 penny, so cost of 1 apple is?
5x = 10
so,
1X = 10/5
= 2 penny

for 2 variables eqn,
5 apples and 2 orange costs 12 penny
also, 2 apples and 4 orange costs 8 penny
to find individual costs??
5x + 2y = 12
2x + 4y = 8
solve 'em and get (x, y) = (2 ,1)

any such equations can be graphically shown in a graph
so your equation y=mx+b when drawn in graph becomes a line whose slope is m and y-intercept in b
vary different values for x and find y, means finding different points on that line (x1, y1), (x2, y2)...
and solving two such eqns graphically means finding the point where that two lines intersect

Answer 6

If you do make y = 0 in the line equation, then you will solve for the x intercept

Answer 7

x is just the x part of a point. (x,y)
you cannot set x = 0 to find y because x and y are certain points.. they're not always 0. the point could be like, (1, 3)