Using substitution solving polynomial equations, Mathematics

Assignment Help:

Using Substitution Solving Polynomial Equations ?

Solve : (x3 + 4) 2 - 15 (x3 + 4) + 36 = 0.

You might be tempted to multiply everything out and factor. However, there's an easier way. Notice that this equation takes the form

A2 - 15A + 36 = 0,

where A = x3 + 4. You can easily solve this simpler quadratic equation! The left side factors to give

(A - 12)(A - 3) = 0

so A = 12 or A = 3.

Since A = x3 + 4, this is the same as saying

x3 + 4 = 12 or x3 + 4 = 3,

So x3 = 8 or x3 = -1,

which means

x = 2 or x = -1.

Normally, you can do this substitution of A for x3 + 4 in your head. You can simply write:

(x3 + 4) 2 - 15(x3 + 4) + 36 = 0

((x3 + 4) - 12)((x3 + 4) - 3) = 0

x3 + 4 = 12 or x3 + 4 = 3,

and so on.


Related Discussions:- Using substitution solving polynomial equations

Division, how do you turn 91 divided by730 into a compatible number

how do you turn 91 divided by730 into a compatible number

Percents, write as a percent 6/10

write as a percent 6/10

Using pythagorean theorem solve z 2 = ( x + y )2 + 3502, Two people on bik...

Two people on bikes are at a distance of  350 meters.  Person A begin riding north at a rate of 5 m/sec and 7 minutes later on Person B begin riding south at 3 m/sec.  Determine th

SHARES AND DIVIDEND, i am a student of class 10 and need help for making my...

i am a student of class 10 and need help for making my project on shares and dividend

Measures of skewness-measure of central tendency, Measures Of Skewness ...

Measures Of Skewness - These are numerical values such assist in evaluating the degree of deviation of a frequency distribution from the general distribution. - Given are t

Binomial, how do you find the co=efficent when there are two brackets invol...

how do you find the co=efficent when there are two brackets involved?

Write down the system of differential equations, Write down the system of d...

Write down the system of differential equations for mass system and the spring above. Solution To assist us out let's first take a rapid look at a situation wherein both of

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd