Question

Please help fassssst

Answer 1

`(9)/(2)`

Explanation:

You can do this using the quadratic equation:

`x =\frac{-b\pm\sqrt{b^(2)-4ac}}{2a}`

Let's first setup our expression:

4x² + 12x = 135

the quadratic formula is:

ax² + bx + c = 0

4x² + 12x - 135 = 0

Then:

a = 4

b = 12

c = -135

Now we plug in our coefficients and solve:

`x =\frac{-12\pm\sqrt{12^(2)-4(4)(-135)}}{2(4)}`

We solve for both to determine the positive one:

`x =\frac{-12+ \sqrt{12^(2)-4(4)(-135)}}{2(4)}`
`x =\frac{-12- \sqrt{12^(2)-4(4)(-135)}}{2(4)}`

`x =(-12+ √(144+2160))/(8)`
`x =(-12- √(144+2160))/(8)`

`x =(-12+ √(2304))/(8)`
`x =(-12- √(2304))/(8)`

`x =(-12+ 48)/(8)`
`x =(-12- 48)/(8)`

`x =(36)/(8) = (9)/(2)`
`x =(-60)/(8) = (-15)/(2)`

So if you are looking for a positive solution, just take the positive one as x.