Answer:
86
Step-by-step explanation:
Firstly,
Average = Sum/Number of Numbers
Since 7 grades' average is 77, so we can say:
77 = Sum/7
Hence, Sum = 77 * 7 = 539
Now,
81 - 18 = 63 [63 marks were recorded incorrectly. actual sum would be 63 more]
So,
Actual Sum should be 539 + 63 = 602
Actual Average = 602 / 7 = 86
Hence, actual report card average would be 86
Answer:
Step-by-step explanation:
3(x+2) -10 = 4x + 6 +x
3x +6 -10 = 5x+6
-10 = 2x
x = -5
One solution
Answer:C-2 lines of symmetry