X + y = 40
y = 9x
x + 9x = 40 (substitute 9x for y in 1st equation)
10 x = 40
x = 4
4 + y = 40 (substitute 4 for x in 1st equation)
y = 36
Answer:
85.7
Step-by-step explanation:
Given that two sections of a class took the same quiz. Section A had 15 students who had a mean score of 80, and Section B had 20 students who had a mean score of 90.
Section A total score = 15*80=1200
Section B total score 20*90 = 1800
Overall total score=3000
Overall total students = 15+20 =35
Hence overall mean =
rounding off to one decimal place
overall mean = 85.7
Answer:
2
Step-by-step explanation:
Two negatives makes a positive, - (-6) can be rewritten as +6 or simply just 6.
Proceed to do simple calculations, 6 - 4 = 2.