Q. If x(x−3)=−1 then the value of x3(x3−18) will be,
Given Equation: We are given the equation x(x−3)=−1.To find the value of x3(x3−18), we first need to find the value of x.Let's solve the given equation for x.x2−3x+1=0This is a quadratic equation, and we can solve it using the quadratic formula: x=2a−b±b2−4ac, where a=1, b=−3, and c=1.
Quadratic Formula: Calculate the discriminant b2−4ac of the quadratic equation.Discriminant = (−3)2−4(1)(1)Discriminant = 9−4Discriminant = 5The discriminant is positive, so we have two real and distinct solutions for x.
Discriminant Calculation: Apply the quadratic formula to find the two solutions for x.x=(2⋅1)−(−3)±5x=23±5So, the two solutions for x are 23+5 and 23−5.
Solving Quadratic Equation: Now we need to find the value of x3(x3−18) for each solution of x. Let's first consider x=23+5. We will calculate x3 and then use it to find x3(x3−18). x3=(23+5)3 This involves expanding the cube of a binomial.
First Solution Calculation: Expand the cube of the binomial (3+5)/2. x3=[(3+5)/2]3 x3=(3/2+5/2)3 x3=(3/2)3+3∗(3/2)2∗(5/2)+3∗(3/2)∗(5/2)2+(5/2)3 This step involves binomial expansion and simplification.
Second Solution Calculation: Simplify the expression for x3. x3=827+3(49)(25)+3(23)(45)+855 x3=827+16275+1645+855 x3=(1627+45)+(16275+105) x3=1672+16375 x3=29+16375 Now we have the value of x3 for the first solution.
Correcting Approach: Repeat the process for the second solution x=23−5.x3=(23−5)3This involves expanding the cube of a binomial, similar to the previous steps.
Correcting Approach: Repeat the process for the second solution x=23−5. x3=[23−5]3 This involves expanding the cube of a binomial, similar to the previous steps.Expand the cube of the binomial 23−5. x3=[23−5]3 x3=(23−25)3 x3=(23)3−3(23)2(25)+3(23)(25)2−(25)3 This step involves binomial expansion and simplification.
Correcting Approach: Repeat the process for the second solution x=23−5. x3=[23−5]3 This involves expanding the cube of a binomial, similar to the previous steps.Expand the cube of the binomial 23−5. x3=[23−5]3 x3=(23−25)3 x3=(23)3−3(23)2(25)+3(23)(25)2−(25)3 This step involves binomial expansion and simplification.Simplify the expression for x3. x3=827−3(49)(25)+3(23)(45)−585 x3=827−16275+1645−855 x3=1627+45−16275+105 x3=[23−5]30 x3=[23−5]31 Now we have the value of x3 for the second solution.
Correcting Approach: Repeat the process for the second solution x=23−5. x3=(23−5)3 This involves expanding the cube of a binomial, similar to the previous steps.Expand the cube of the binomial 23−5. x3=(23−5)3 x3=(23−25)3 x3=(23)3−3(23)2(25)+3(23)(25)2−(25)3 This step involves binomial expansion and simplification.Simplify the expression for x3. x3=827−3(49)(25)+3(23)(45)−585 x3=827−16275+1645−855 x3=1627+45−16275+105 x3=(23−5)30 x3=(23−5)31 Now we have the value of x3 for the second solution.Now we need to find the value of x3=(23−5)33 for each solution of x3=(23−5)34. However, we realize that we made a mistake in the approach. We do not need to find the individual solutions for x3=(23−5)34 to calculate x3=(23−5)33 because we can use the given equation x3=(23−5)37 to simplify the expression directly. We need to correct our approach and use the given equation to simplify x3=(23−5)33 without finding the individual values of x3=(23−5)34.
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