To factor quadratic equations of the form ax^2+bx+c=y, you must find two values, j and k, which satisfy two conditions.
jk=ac and j+k=b
The you replace the single linear term bx with jx and kx. Finally then you factor the first pair of terms and the second pair of terms. In this problem...
2k^2-5k-18=0
2k^2+4k-9k-18=0
2k(k+2)-9(k+2)=0
(2k-9)(k+2)=0
so k=-2 and 9/2
k=(-2, 4.5)
=d/dx((t^4-6)^3) * (t^3+6)^4 + d/dx((t^3+6)^4) * (t^4-6)^3
=3*(t^4-6)^2 * (t^3+6)^4 * d/dx(t^4-6) + 4*(t^3+6)^3 * (t^4-6)^3 * d/dx(t^3+6)
=3*(t^4-6)^2 * (t^3+6)^4 * 4t^3 + 4*(t^3+6)^3 * (t^4-6)^3 * 3t^2
Simplify that if youd like
Not sure but I believe letter B) 3+4 is rational since the answer is 7 and 7 is a rational number and it can be expressed as a quotient. The sum of a rational number and an irrational number is irrational. The sum of two rational numbers is rational