Question

Solve using the quadratic formula...
9x2 - 4 + 7x

Answer 1

`x=-(7)/(18)+\frac{\sqrt[]{193} }{18}` which is the same as
`x=0.38`

or

`x=-(7)/(18)-\frac{\sqrt[]{193} }{18}` which is the same as
`x=-1.16`

Explanation:

`9x^2-4+7x=0`

Rearranging...

`9x^2+7x-4=0`

a=9

b=7

c=-4

`x=\frac{-b\frac{+}{}\sqrt[]{b^2-4ac} }{2a}`

`x=\frac{-7\frac{+}{}\sqrt[]{(7)^2-4(9)(-4)} }{2(9)}`

`x=\frac{-7\frac{+}{}\sqrt[]{49+144} }{18}`

`x=\frac{-7\frac{+}{}\sqrt[]{193} }{18}`

----------------------------------------

`x=-(7)/(18)+\frac{\sqrt[]{193} }{18}`

or

`x=-(7)/(18)-\frac{\sqrt[]{193} }{18}`

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If you need decimals, you can solve;

`x=0.38\\`

or

`x=-1.16`

Answer 2

x=0.4, x=-1.2

Explanation: