Question 337491
(5.9x^3+3.4x^2-7)-(2.9x^3-9.6x^2+3)
=(45x^3 +12x^2 -7) -(18x^3-54x^2+3)
remove the paranthesis
=45x^3+12x^2 -7 -18x^3 +54x^2 -3
take the like terms together and simplify

45x^3-18x^3 +12x^2+54x^2 -7-3
 => (45-18)x^3 + (12+54)x^2 -(7+3)
 => 27x^3 + 66x^2 -10