pls help me solve the maths question,thanks.?

when you simplify, you will get 2x^2 - 3x - 21=0. if you solve this you will get (3 - 2root42)/4 and (3 + 2root42)/4. easy one only. glad to be helpful. give my ten points then

If you meant 2x/(3 - 1) = 7/x

2x/(3 - 1) = 7/x

2x×x = 7×2

2x^2 = 14

x^2 = 7

x = ±√7

so x = 2.64575 or -2.64575

Or did u mean 2x/3 - 1 = 7/x

2x/3 - 1 = 7/x

x(2x/3 - 1) = 7

2x^2/3 - x = 7

x^2 - 3x/2 = 21/2

(x - 3/4)^2 = 21/2 + 9/16

(x - 3/4)^2 = 168/16 + 9/16

(x - 3/4)^2 = 17716

x - 3/4 = ±√(177/16)

x = 3/4 ± √(177/16)

so x = 4.07603 or -2.57603

Hope this helps you.

*βω*

f you meant 2x/(3 - 1) = 7/x

2x/(3 - 1) = 7/x

2x×x = 7×2

2x^2 = 14

x^2 = 7

x = ±√7

so x = 2.64575 or -2.64575

Or did u mean 2x/3 - 1 = 7/x

2x/3 - 1 = 7/x

x(2x/3 - 1) = 7

2x^2/3 - x = 7

x^2 - 3x/2 = 21/2

(x - 3/4)^2 = 21/2 + 9/16

(x - 3/4)^2 = 168/16 + 9/16

(x - 3/4)^2 = 17716

x - 3/4 = ±√(177/16)

x = 3/4 ± √(177/16)

so x = 4.07603 or -2.57603

Hope this helps you.

*βω*

I'll do it, the others are wrong or not complete.

2x / 3 - 1 = 7 / x

2x - 3 = 21 / x

2x² - 3x = 21

2x² - 3x - 21 = 0

a = 2 ; b = - 3 ; c = - 21

Formula x = [- b ± √ (b² - 4ac) ] / 2a

x = ( 3 ± √ 177 ) / 4

There'll be two answers.

x1 = ( 3 + √ 177 ) / 4

= 4.076 (3dp)

x2 = ( 3 - √ 177 ) / 4

= - 2.576 (3dp)

SO x = 4.076 , x = - 2.576

I calculated the same values of x as Jeoffey F and Jasher36.

Rather than repeat the calculations, I will provide the proof.

If x = +4.076, the left side of the equation is equal to:

(((2 times +4.076) divided by 3) -1) =

(8.152 divided by 3) -1 = 2.717 -1 = 1.717

Again, if x = +4.076, the right side of the equation is equal to:

7 divided by +4.076 = 1.717

Since left side balances with right side, the solution is correct.

If x = -2.576, the left side of the equation is equal to:

(((2 times -2.576)divided by 3) -1) =

(-5.152 divided by 3) - 1 = -1.717 -1 = -2.717

Again, if x = -2.576, the right side of the equation is equal to:

7 divided by -2.576 = -2.717

Since the left side balances with the right side, this solution is also correct.

you should use parenthesis.

(2x/3)-1 = 7/x. This will be a quadratic; multiply by 3x.

2x^2 - 3x = 21; so 2x^2 - 3x -21 = 0:

using the quadratic formula, I get the following:

x = 4.076... or -2.576...

x + 2y = 13 ----> (1) 3x - 5y = -9 ----> (2) take (1) and find the x value x + 2y = 13 x = 13 - 2y -----> (3) apply (3) onto (2) i.e. take out the x and put 13 - 2y 3(13-2y)-5y = -9 expand the brackets 39 - 6y -5y = -9 39 - 11y = -9 39 + 9 = 11y 48 = 11y y = 48/11 insert your answer into (3) x = 13 - 2(48/11) x = 13 - 96/11 x = 239/11

2x/3 -1 = 7/x get the lcd x and 3

2x/x - 1 = 7/3

2 -1x/3 = 7/3

2 - 7/3 = 1x/3

-1/3 = 1x/3

-1 = x

2x/3 - 1 = 7/x

2x/3 - 7/x = 1

3x(2x/3 - 7/x) = 3x(1)

2x^2 - 21 = 3x

2x^2 - 3x - 21 = 0

x = [-b ±√(b^2 - 4ac)]/2a

a = 2

b = -3

c = -21

x = [3 ±√(9 + 168)]/4

x = [3 ±√177]/4

x = [3 ±13.3]/4 (approx.)

x = [3 + 13.3]/4

x = 16.3/4

x = 4.075

x = [3 - 13.3]/4

x = -10.3/4

x = -2.575

∴ x = 4.075 , -2.575

form quadratic equation and then find roots..