Okay I am doing algebra with variables, I cannot remember how to do them. What do I have to do to get the anwer?? my first one is -12x = 3 (y - 3) I know the answer but I need to know how do you get the answer??
2006-11-06 17:53:24 · 8 answers · asked by Anonymous in Science & Mathematics ➔ Mathematics
-12x = 3(y - 3)
You want y with a coeficient of 1, which the expression inside the parenthesis already has, so divide both sides by 3:
-12x/3 = 3(y - 3)/3
-4x = y - 3
Now you want y standing alone, so add 3 to both sides:
-4x + 3 = y - 3 + 3
-4x + 3 = y
Swap sides to finish in standard (y = mx + b) form:
y = -4x + 3
2006-11-06 18:12:08 · answer #1 · answered by Helmut 7 · 1⤊ 0⤋
First of all you require as many equations as the variables.
Here there are 2 variable so you can't find the answer unless another equation is given.
As for solving,
1)first find any variable in terms of the other
here, -12x=3(y-3)
=>x=3(3-y)/12.............(1)
2)Now, substitute this value in the second equation and you'll get a linear equation! Solve it find y then using the value of y fond x by substituting the value in equation (1).
By the way chic...has given the wrong solution the signs in the 5th equation are wrong!
2006-11-06 21:45:56 · answer #2 · answered by sushant 3 · 0⤊ 0⤋
Solve,
-12x = 3 (y - 3)
Expand RHS,
-12x = 3y - 3
Add 3 to both sides,
-12x + (3) = 3y - 3 + (3)
-12x + 3 = 3y
Rearrange,
3y = -12x + 3
Divide both sides by 3,
(3y)/3 = (-12x + 3)/3
3y/3 = -12x/3 + 3/3
Simplify,
y = -4x + 1
2006-11-06 19:25:20 · answer #3 · answered by ideaquest 7 · 0⤊ 0⤋
-12x=3(y-3)
-12x=3y-9
divide both sides by -12, so that x will be left on one side of the equation,
(-12x/-12)=(3y-9)/-12
x=(3y/-12)-(9/-12)
x=(1/4)y-(3/4)y
then, substitute the value of x in the original equation,
-12x=3(y-3)
-12[(1/4)y-(3/4)y]=3(y-3)
do the operation.
-3y+9y=3y-9
6y-3y= -9
3y= -9
divide both sides by 3,
y= -3
thus,
-12x=3(y-3)
-12x=3(-3)-9
-12x= -9-9
-12x= -18
divide by -12
x= -18/12
x= -3/2....
therefore, x= -3/2 & y= -3...
2006-11-06 18:34:49 · answer #4 · answered by chic_84 2 · 0⤊ 0⤋
Ok, the sides are already factored so think about removing any common factors,
-12x = 3(y-3)
3 is common to all terms throughout the eq. so,
-4x = y - 3
then,
y = 3 - 4x
2006-11-06 18:39:02 · answer #5 · answered by yasiru89 6 · 0⤊ 0⤋
I'm a little rusty but here's how I'd work the problem:
-12x=3(y-3)
-12x/3=-4x and 3(y-3)/3=(y-3)
-4x=(y-3)
x=(y-3)/-4
I think
2006-11-06 18:16:35 · answer #6 · answered by Dee L 2 · 0⤊ 0⤋
-12x=3(y-3)
you need to multiply out the brackets and form a simultaneous equation.
2006-11-06 18:17:27 · answer #7 · answered by Rach 1 · 0⤊ 0⤋
-12x = 3y - 9
-4x = y - 3
2006-11-07 00:14:07 · answer #8 · answered by Anonymous · 0⤊ 0⤋