Final answer:
To create an equation with no solution, we need to set up the equation so that the coefficients of the x terms cancel each other out. In this case, the correct option is (b) -18.
Step-by-step explanation:
To create an equation with no solution, we need to set up the equation so that the coefficients of the x terms cancel each other out. In this case, we can achieve this by multiplying 4x and 7 by 5, and multiplying x and 21 by -2. The equation then becomes: 20x + 35 - 2x = -2x - 42. Simplifying further, we get 18x + 35 = -2x - 42. Since we can't find a value of x that satisfies this equation, it has no solution. Therefore, the correct option is (b) -18.