Answer:
A, because m is less than 4.4 so 4.4, is gonna be greater
First term ,a=4 , common difference =4-7=-3, n =50
sum of first 50terms= (50/2)[2×4+(50-1)(-3)]
=25×[8+49]×-3
=25×57×-3
=25× -171
= -42925
derivation of the formula for the sum of n terms
Progression, S
S=a1+a2+a3+a4+...+an
S=a1+(a1+d)+(a1+2d)+(a1+3d)+...+[a1+(n−1)d] → Equation (1)
S=an+an−1+an−2+an−3+...+a1
S=an+(an−d)+(an−2d)+(an−3d)+...+[an−(n−1)d] → Equation (2)
Add Equations (1) and (2)
2S=(a1+an)+(a1+an)+(a1+an)+(a1+an)+...+(a1+an)
2S=n(a1+an)
S=n/2(a1+an)
Substitute an = a1 + (n - 1)d to the above equation, we have
S=n/2{a1+[a1+(n−1)d]}
S=n/2[2a1+(n−1)d]
Answer:
there are 15 marbles in the bag
Step-by-step explanation:
If i did the math correctly one number is 50
19 has two factors: 1, 19
21 has four factors: 1, 3, 7, 21
23 has two factors: 1, 23
And we need a number that has more than four factors and is greater than 25.
Factors of 50- 1, 2, 5, 10, 25, 50
50has six factors and is greater than 25.
Answer:
(1/5)x-5.4=y
Step-by-step explanation:
mx+b=y
m=(1/5)
(-8,-7)=(x,y)
(1/5)(-8)+b=(-7)
-1.6+b=-7
b=-5.4
(1/5)x-5.4=y
