Answer:
77 boxes
Step-by-step explanation:
1000/13= 76.9230769
They can't sell part of a box and a little extra money never hurt any one.
Answer:
x=9
Step-by-step explanation:3x-5+x=31
3x+x=31+5
4x=36
x=36/4
x=9
Answer:
2x+3x=180°
that is 5x=180°meaning x=32°
Answer:
Step-by-step explanation:
The summation formula ( arithmetic sequence when the first terme is : A1 = 13
and the coomo diff is d= -4
Sn = n/2(A1 +An)
An = A1+(n-1)d
An = 13 +(n-1)(-4)
An = -4n +17
Sn = n/2(13+17-4n) = n/2(30-4n)
Sn = -2n² +15n
in this exercice : n =4 S4 = -2(4)² +15(4) = -32+60 = 28
verify : 13 + 9 + 5 + 1 =28 ......right
