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:
see below
Step-by-step explanation:
x+ 7.05 = 45.3
Subtract 7.05 from each side
x+ 7.05-7.05 = 45.3-7.05
x =38.25
Let x be the number
x+3.5 = -4.3
Subtract 3.5 from each side
x+3.5 - 3.5 = -4.3-3.5
x = -7.8
x is the cost of the drawing tablet
x+ 3.95 = 6.94 correct
The second equation add the total cost plus the cost of the drawing tablet and sets it equal to the cost of the pencils. This is not correct
6.94+x = 3.95 incorrect
The obtained transformed data will show a linear relation when you graph log(y) vs x
This is the mathematical demonstration:
Exponential function: y= A (B)^x
log(y) = log A + x log B
log(y) = log A + (logB)x
log A is a constant and is the vertical axis-intercept
logB is a constant and is the slope of the graph
x is the independent variable
log A is a constant,
Answer:
Exact Form:
39
/10
Decimal Form:
3.9
Mixed Number Form:
3 9/10
Step-by-step explanation:
