Question
Solve the equation
x1=21−342,x2=21+342
Alternative Form
x1≈1.557778,x2≈40.442222
Evaluate
422x−7×x−34x−9=2x
Multiply the terms
More Steps

Multiply the terms
422x−7×x
Multiply the terms
42(2x−7)x
Multiply the terms
42x(2x−7)
42x(2x−7)−34x−9=2x
Multiply both sides of the equation by LCD
(42x(2x−7)−34x−9)×42=2x×42
Simplify the equation
More Steps

Evaluate
(42x(2x−7)−34x−9)×42
Apply the distributive property
42x(2x−7)×42−34x−9×42
Simplify
x(2x−7)+(−4x+9)×14
Multiply the terms
More Steps

Evaluate
(−4x+9)×14
Apply the distributive property
−4x×14+9×14
Calculate
−56x+9×14
Calculate
−56x+126
x(2x−7)−56x+126
Expand the expression
More Steps

Calculate
x(2x−7)
Apply the distributive property
x×2x−x×7
Multiply the terms
2x2−x×7
Use the commutative property to reorder the terms
2x2−7x
2x2−7x−56x+126
Subtract the terms
More Steps

Evaluate
−7x−56x
Collect like terms by calculating the sum or difference of their coefficients
(−7−56)x
Subtract the numbers
−63x
2x2−63x+126
2x2−63x+126=2x×42
Simplify the equation
More Steps

Evaluate
2x×42
Simplify
x×21
Use the commutative property to reorder the terms
21x
2x2−63x+126=21x
Move the expression to the left side
2x2−63x+126−21x=0
Subtract the terms
More Steps

Evaluate
−63x−21x
Collect like terms by calculating the sum or difference of their coefficients
(−63−21)x
Subtract the numbers
−84x
2x2−84x+126=0
Substitute a=2,b=−84 and c=126 into the quadratic formula x=2a−b±b2−4ac
x=2×284±(−84)2−4×2×126
Simplify the expression
x=484±(−84)2−4×2×126
Simplify the expression
More Steps

Evaluate
(−84)2−4×2×126
Multiply the terms
More Steps

Multiply the terms
4×2×126
Multiply the terms
8×126
Multiply the numbers
1008
(−84)2−1008
Rewrite the expression
842−1008
Evaluate the power
7056−1008
Subtract the numbers
6048
x=484±6048
Simplify the radical expression
More Steps

Evaluate
6048
Write the expression as a product where the root of one of the factors can be evaluated
144×42
Write the number in exponential form with the base of 12
122×42
The root of a product is equal to the product of the roots of each factor
122×42
Reduce the index of the radical and exponent with 2
1242
x=484±1242
Separate the equation into 2 possible cases
x=484+1242x=484−1242
Simplify the expression
More Steps

Evaluate
x=484+1242
Divide the terms
More Steps

Evaluate
484+1242
Rewrite the expression
44(21+342)
Reduce the fraction
21+342
x=21+342
x=21+342x=484−1242
Simplify the expression
More Steps

Evaluate
x=484−1242
Divide the terms
More Steps

Evaluate
484−1242
Rewrite the expression
44(21−342)
Reduce the fraction
21−342
x=21−342
x=21+342x=21−342
Solution
x1=21−342,x2=21+342
Alternative Form
x1≈1.557778,x2≈40.442222
Show Solution
