Need to solve equasion for Y. 4y + 3X = 7     

11 Answers | Add Yours

neela's profile pic

neela | High School Teacher | (Level 3) Valedictorian

Posted on

Two varibles x and y , in degree one, is a linear equation and is generally written like, ax+by+c=0. The given equation is 4y+3x=-7 can also be written  as , 3x+4y-7=0.

Solution:

To solve the equation for y, we subtract 3x from both sides as a 1st step.

4y+3x -3x=7 -3x

4y=7-3x

Divide both sides by 4.

4y/4=(7-3x)/4

y=7/4 - (3/4)x     0r     y =0.75-0.75x

Now give any value to x , and you get y value:

 

X:     0        1         2          3            4           5

y= 0.75    1         0.25   -0.50    -1.25     -2

Plot the values you get a steadily decreasing line  for y as x increases.

 

 

 

 

melissa1106's profile pic

melissa1106 | Student, Grade 11 | (Level 1) Salutatorian

Posted on

4y+3x=7

In order to solve for for y you need to isolate y.

subtract 3x from the other side.

4y=-3x+7

then divide everything by four so you can get what y is equal to:

y=-3/4x+7/4

or in decimal it is equal to:
Y=-0.75x=1.75

your slope for this equation is equal to  - 3/4 and your y intercept is (0,1.75)

atyourservice's profile pic

atyourservice | Student, Grade 11 | (Level 3) Valedictorian

Posted on

4y + 3X = 7

since you are solving for y move the x to the other side

4y = 7 - 3x

divide by 4

y = 7/4 - 3x/4

y = -0.75x + 1.75

Wiggin42's profile pic

Wiggin42 | Student, Undergraduate | (Level 2) Valedictorian

Posted on

4y + 3x = 7

To solve for y, first isolate all the y terms. In this case, there is only one y term. so: 

4y = 7 - 3x

Now we need to get rid of the 4. Since y is being multiplied by 4, we need to undo this. The way to undo multiplication is through division. So, divide both sides by 4. 

y = (7 - 3x)/4

Jyotsana's profile pic

Jyotsana | Student, Grade 10 | (Level 1) Valedictorian

Posted on

4y+3x=7

4y+3x-3x=7-3x

4y=7-3x

4y/4=7/4-3x/4

y=1.75-0.75x

and you just plug anything to for x to find the answer for y

revolution's profile pic

revolution | College Teacher | (Level 1) Valedictorian

Posted on

4y+3x=7. You need to make the subject be Y, so push all the other values to one side.

4y+3x=7

4y=7-3x

y=(7-3x)/4

y=-3/4x+7/4 (mx+c)

The y-intercept is 7/4, slope is -3/4

The point would be (X,7/4) unknown x-value only if you plot any possible number inside.

 

kmieciakp's profile pic

kmieciakp | High School Teacher | (Level 2) Assistant Educator

Posted on

Actually, the y intercept means the place the line goes through the y axis when x= 0.  So again, the point would be (0, 7/4).  (-3/4) is the slope of the line, so to find the next point on the line, just go up three on the y axis (to 11/4, then to 15/4, and finally to 19/4) and then over to the left 4 spaces on the x axis, to -4.  So the next point would be (-4, 19/4).

If you want to find the x intercept, the point the line crosses on the x axis when y=0, just plug in 0 for y and solve the equation for x.

0= (-3/4)x + 7/4

-7/4=-3/4x

7/4=3/4x

(4/3)7/4 = x

7/3 = x.

So the line crosses the x axis at (7/3, 0).

stevenjohnson's profile pic

stevenjohnson | Student, Grade 9 | eNotes Newbie

Posted on

4y+3x=7 then u minus the 3x

4y=7-3x then u divide by 4 on each side

y=7/4-3/4x

so the y-intercept is 7/4 and theanswer is (-3/4x , 7/4 )

 

kmieciakp's profile pic

kmieciakp | High School Teacher | (Level 2) Assistant Educator

Posted on

4y=7-3x

y=7/4-3x/4

y=--3/4(x) +7/4

so y intercept is 7/4 (reduced: 1 and 3/4)

plot (0, 7/4)

We’ve answered 318,950 questions. We can answer yours, too.

Ask a question