: Stage A and Stage B. Stage A's thrust is defined by the expression 11.2x + 6.4 and Stage B's thrust is defined by the expression 7.4x − 2.9.

18.6x + 3.6

Explanation:

A rocket scientist needs to find the overall thrust of a new rocket design. The rocket has two stages: Stage A and Stage B. Stage A's thrust is defined by the expression 11.2x + 6.4 and Stage B's thrust is defined by the expression 7.4x − 2.9.

Solution:

The rocket thrust is the force that helps in moving the rocket through air and through space. For a multistage rocket, the overall thrust is gotten by summing all the thrust experienced in each of the stages.

Hence the overall thrust for this problem is given by the equation:

Overall thrust = Stage A thrust + stage B thrust

Overall thrust = (11.2x + 6.4) + (7.4x − 2.9)

Overall thrust = 18.6x + 3.6