Changing the subject (advanced algebra)?

Question

Make x the subject.
5 ( x - 3 ) = y ( 4 - 3x )
How do you do it? Can you please show the steps you took.

Answer 1

Expand:
... 5x - 15 = 4y - 12xy

Collect all x's on the left side:
... 5x + 12xy = 4y + 15

Factor out x:
... x (5 + 12y) = 4y + 15

Divide:
... x = (4y + 15) / (12y + 5).

Answer 2

Expand:
5x - 15 = 4y - 3xy

Add 15 to both sides:
5x = 4y - 3xy + 15

Add 3xy to both sides:
5x + 3xy = 4y + 15

Factor out x on the left hand side:
x(5 + 3y) = 4y + 15

Divide by (5 + 3y)
x = 4y + 15/5 + 3y

Hope this helps p.s. whenever the subject needed appears in more than one place get them all onto one side then factor out.

Answer 3

Remember to maintain EQUALITY in an Equation whatever you dto RHS (Right Hand Side) you MUST DO the SAME TO LHS (Left Hand Side)


You began with
5(x - 3) = y(4-3x)

Expand {Multiply out both sides]
5x - 15 = 4y - 3xy

Collect terms {Get all the 'x' and 'y' quantities together}
[ and add '3xy' and '15' to Both Sides]

5x + 3xy = 4y + 15

Factorise LHS

x(5 + 3y) = 4y + 15

Divide both sides by (5 + 3y) {Gets rid of term on LHS}

x = {[4y + 15] / {5 + 3y]}

This is as far as you can take the re-arrangement of the original expression. :-)

Answer 4

always expand the brackets first:
5x -15 = 4y - 3xy

Now then, there are 2 terms containing an x so you need to get on the same side of the equation. first add 15 to both sides:
5x = 4y - 3xy + 15

And next add 3xy to both sides:
5x+3xy = 4y + 15

factorise so there is only 1 x
x(5 + 3y) = 4y + 15

Now just divide through by 5 + 3y
x = (4y + 15) / (5 + 3y)

The brackest aren't necessary but make it clearer

i hope this helps :)

Answer 5

a million: Subtract 5x from the two aspects: 2x-5x=5x-5x-7y -3x = -7y Divide by -3: x=7y/3 #2: Divide the comprehensive expression by x: 5x/x - 3/x = 4xy/x +2/x 5 - 3/x = 4y + 2/x deliver the x-words to the RHS and each thing else to the LHS: -5/x = 4y - 5 Invert the comprehensive expression: -x/5 = a million/(4y-5) Multiply by -5: x = -5/(4y-5) #3: Subtract 7x from the two aspects: 3x-7x=7x-7x+6/(2y) -4x = 6/(2y) Divide by -4: x = -6/(8y)

Answer 6

People have told u the answer so I'm going to give you two more helpful hints,

1) When doing this first get all your x terms on one side and then factorise. (You may only need to divide in simplar problems)

2) If you think this is advanced algebra you're in for a shock if you keep the maths up!

Good luck!

Answer 7

5 ( x - 3 ) = y ( 4 - 3x )
5x - 15 = 4y - 3xy
5x + 3xy = 4y + 15
x(5 + 3y) = 4y + 15
x = (4y + 15)/(5 + 3y)

Answer 8

5(x - 3) = y ( 4 - 3x)
5x - 15 = 4y - 3xy
5x + 3xy = 4y + 15
x(5+3y) = 4y + 15
x = (4y+15)/(5+3y)

Answer 9

5(x - 3) = y ( 4 - 3x)
5x - 15 = 4y - 3xy
5x + 3xy = 4y + 15
x(5+3y) = 4y + 15
x = (4y+15)/(5+3y)

Answer 10

you can se this out of the given equation:
5x-5=4y-3xy
5x+3xy=4y+5
x(5+3y)= 4y+5

x=(4y+5)/(3y+5)
This give you an expression of x as a function of y.
The of x is 1 when y=0.

Answer 11

times it out on both sides then collect like terms

so....

5x -15 = 4y -3xy
5x + 3xy = 4y+15 then factorise, taking out x
x (5 + 3y) = 4y +15 then divide, leaving x

x = 4y +15 / (5 + 3y)