Answer :
Final answer:
To find the correct equations among the options given, we need to substitute the known values and use logic to determine consistency. Options b. (f = 7) and a. are correct, while options c. (cf = 59) and d. (f = 42) are inconsistent with b. and thus incorrect.
Explanation:
The solution to the equations provided is determined by using substitution and considering the consistency of units in physics equations. Equation b. tells us that f = 7. We can directly see that option d. f = 42 is incorrect because it contradicts b. Looking at option a., if c + f = 10 and we already know f = 7, then c must be 3 to satisfy the equation (c + 7 = 10). Option c. presents cf = 59, which implies that c multiplied by f equals 59. Using the value of f from equation b., we can solve for c to see if it also satisfies this equation: 7c = 59, thus c would be 59/7, which is approximately 8.43, not 3 as previously calculated. Therefore, option c. is also incorrect because it does not align with the conclusion we drew from options a. and b.
