Given:
[tex]\left(12x^5+Rx^4+Px^2-5\right)+\left(-6x^5-4x^4+13x+Q\right)=6x^5+3x^4+9x^2+13x+7[/tex]
To find:
The values of R, P and Q.
Solution:
We have,
[tex]\left(12x^5+Rx^4+Px^2-5\right)+\left(-6x^5-4x^4+13x+Q\right)=6x^5+3x^4+9x^2+13x+7[/tex]
On combining like terms, we get
[tex](12x^5-6x^5)+(Rx^4-4x^4)+Px^2+13x+(Q-5)=6x^5+3x^4+9x^2+13x+7 [/tex]
[tex]6x^5+(R-4)x^4+Px^2+13x+(Q-5)=6x^5+3x^4+9x^2+13x+7 [/tex]
On comparing the coefficients of [tex]x^4[/tex], we get
[tex]R-4=3[/tex]
[tex]R=3+4[/tex]
[tex]R=7[/tex]
On comparing the coefficients of [tex]x^2[/tex], we get
[tex]P=9[/tex]
on comparing the constants, we get
[tex]Q-5=7[/tex]
[tex]Q=7+5[/tex]
[tex]Q=12[/tex]
Therefore, [tex]R=7,P=9[/tex] and [tex]Q=12[/tex].