Final answer:
To solve the equation '6s + R = 21' for 's', we isolate 's' and then check the provided options. The correct value of 's' is found to be 3, which makes R equal to 3 as well, corresponding to option A.
Step-by-step explanation:
The problem is to solve for 's' in the equation 6s + R = 21. To do this, we need to isolate 's' by subtracting 'R' from both sides of the equation, giving us 6s = 21 - R. Then we divide both sides by 6, yielding s = (21 - R) / 6. To find 's' and substitute it back into the equation to solve for 'R', we can check each provided option:
- A) If s = 3, then 21 - R = 6*3, which means R = 3.
- B) If s = 2, then 21 - R = 6*2, which means R = 9.
- C) If s = 4, then 21 - R = 6*4, which means R = 9, which is wrong. This option is incorrect.
- D) If s = 5, then 21 - R = 6*5, which means R = -9, which also is incorrect.
The only correct options where the value of 's' and the value of 'R' correctly resolve the equation to 21 are A) and B). Since the options are exclusive and only one can be correct, we can confirm the correct answer by substituting the values of 's' into the original equation.
By substituting s = 3 into 6s + R = 21, we get 6*3 + R = 21 which results in R = 21 - 18 = 3. Therefore, the correct answer is A) s = 3, R = 3.