Question
Solve the equation(The real numbers system)
n∈/R
Alternative Form
No real solution
Evaluate
7(2n−3)=21n2×1
Multiply the terms
7(2n−3)=21n2
Swap the sides
21n2=7(2n−3)
Expand the expression
More Steps

Evaluate
7(2n−3)
Apply the distributive property
7×2n−7×3
Multiply the numbers
14n−7×3
Multiply the numbers
14n−21
21n2=14n−21
Move the expression to the left side
21n2−14n+21=0
Substitute a=21,b=−14 and c=21 into the quadratic formula n=2a−b±b2−4ac
n=2×2114±(−14)2−4×21×21
Simplify the expression
n=4214±(−14)2−4×21×21
Simplify the expression
More Steps

Evaluate
(−14)2−4×21×21
Multiply the terms
More Steps

Multiply the terms
4×21×21
Multiply the terms
84×21
Multiply the numbers
1764
(−14)2−1764
Rewrite the expression
142−1764
Evaluate the power
196−1764
Subtract the numbers
−1568
n=4214±−1568
Solution
n∈/R
Alternative Form
No real solution
Show Solution

Solve the equation(The complex numbers system)
Solve using the quadratic formula in the complex numbers system
Solve by completing the square in the complex numbers system
Solve using the PQ formula in the complex numbers system
n1=31−322i,n2=31+322i
Alternative Form
n1≈0.3˙−0.942809i,n2≈0.3˙+0.942809i
Evaluate
7(2n−3)=21n2×1
Multiply the terms
7(2n−3)=21n2
Swap the sides
21n2=7(2n−3)
Expand the expression
More Steps

Evaluate
7(2n−3)
Apply the distributive property
7×2n−7×3
Multiply the numbers
14n−7×3
Multiply the numbers
14n−21
21n2=14n−21
Move the expression to the left side
21n2−14n+21=0
Substitute a=21,b=−14 and c=21 into the quadratic formula n=2a−b±b2−4ac
n=2×2114±(−14)2−4×21×21
Simplify the expression
n=4214±(−14)2−4×21×21
Simplify the expression
More Steps

Evaluate
(−14)2−4×21×21
Multiply the terms
More Steps

Multiply the terms
4×21×21
Multiply the terms
84×21
Multiply the numbers
1764
(−14)2−1764
Rewrite the expression
142−1764
Evaluate the power
196−1764
Subtract the numbers
−1568
n=4214±−1568
Simplify the radical expression
More Steps

Evaluate
−1568
Evaluate the power
1568×−1
Evaluate the power
1568×i
Evaluate the power
More Steps

Evaluate
1568
Write the expression as a product where the root of one of the factors can be evaluated
784×2
Write the number in exponential form with the base of 28
282×2
The root of a product is equal to the product of the roots of each factor
282×2
Reduce the index of the radical and exponent with 2
282
282×i
n=4214±282×i
Separate the equation into 2 possible cases
n=4214+282×in=4214−282×i
Simplify the expression
More Steps

Evaluate
n=4214+282×i
Divide the terms
More Steps

Evaluate
4214+282×i
Rewrite the expression
4214(1+22×i)
Cancel out the common factor 14
31+22×i
Simplify
31+322i
n=31+322i
n=31+322in=4214−282×i
Simplify the expression
More Steps

Evaluate
n=4214−282×i
Divide the terms
More Steps

Evaluate
4214−282×i
Rewrite the expression
4214(1−22×i)
Cancel out the common factor 14
31−22×i
Simplify
31−322i
n=31−322i
n=31+322in=31−322i
Solution
n1=31−322i,n2=31+322i
Alternative Form
n1≈0.3˙−0.942809i,n2≈0.3˙+0.942809i
Show Solution
