Final answer:
The correct answers are options A and D, as these are the points that satisfy their respective linear equations when substituted.
Step-by-step explanation:
The correct answer is option A and D. To determine if the given points are on the graph of the corresponding equations, we can substitute the x and y values of each point into the equation and check if they satisfy the equation.
- For point (2,8) and equation x + 2y = 20:
2 + 2(8) = 2 + 16 = 18, which does not equal 20. Therefore, point (2,8) is not on the graph of x + 2y = 20. - For point (-1,5) and equation x + 2y = 10:
-1 + 2(5) = -1 + 10 = 9, which does not equal 10. Therefore, point (-1,5) is not on the graph of x + 2y = 10. - For point (7,7) and equation 2x - y = 7:
2(7) - 7 = 14 - 7 = 7, which equals 7. Point (7,7) is not listed as an option, so we will not consider it in the final answer. - For point (7,-7) and equation 3x + y = 14:
3(7) + (-7) = 21 - 7 = 14, which equals 14. Therefore, point (7,-7) is on the graph of 3x + y = 14. - For point (1,1) and equation 2x + 6y = 8:
2(1) + 6(1) = 2 + 6 = 8, which equals 8. However, point (1,1) is not listed as an option, so we will not consider it in the final answer.
Thus, the only true statements are options A and D, where the given points satisfy their respective linear equations.