What are the solutions to the equation 21-21x=(5x+4)(x-1) ?

The solutions to the equation 21-21x=(5x+4)(x-1) are x=1,x=-5

Find the zeros of 21-21x=(5x+4)(x-1)

The zeros of 21-21x=(5x+4)(x-1) are x=1,x=-5

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21 - 21 x = (5 x + 4) (x - 1)

x = 1, x = - 5

Solution steps

21 - 21 x = (5 x + 4) (x - 1)

Expand

(5 x + 4) (x - 1) : 5 x^{2} - x - 4

21 - 21 x = 5 x^{2} - x - 4

Switch sides

5 x^{2} - x - 4 = 21 - 21 x

Move

21 x

to the left side

5 x^{2} + 20 x - 4 = 21

Move

21

to the left side

5 x^{2} + 20 x - 25 = 0

Solve with the quadratic formula

x_{1, 2} = \frac{- 20 \pm 2 0 ^{2} - 4 \cdot 5 ( - 25 )}{2 \cdot 5}

2 0^{2} - 4 \cdot 5 (- 25) = 30

x_{1, 2} = \frac{- 20 \pm 30}{2 \cdot 5}

Separate the solutions

x_{1} = \frac{- 20 + 30}{2 \cdot 5}, x_{2} = \frac{- 20 - 30}{2 \cdot 5}

x = \frac{- 20 + 30}{2 \cdot 5} : 1

x = \frac{- 20 - 30}{2 \cdot 5} : - 5

The solutions to the quadratic equation are:

x = 1, x = - 5

x^{2} - 243 x - 486 = 0

6 r^{2} + 8 = - 4 r

9 x^{2} - 3 x = 20

- x^{2} + x - 1 = 0

x^{2} + 8 x - 23 = 0

What are the solutions to the equation 21-21x=(5x+4)(x-1) ?
The solutions to the equation 21-21x=(5x+4)(x-1) are x=1,x=-5
Find the zeros of 21-21x=(5x+4)(x-1)
The zeros of 21-21x=(5x+4)(x-1) are x=1,x=-5