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]
Since there are no numbers, i will assume that the length of recess is 1 minute, or x. if social studies is 4 more than 2 times the length of recess, we can use the equation x*2+4 to solve the problem. the end result will be 6 minutes. Social studies is 6 minutes longer than recess
Answer:
6 and 4
Step-by-step explanation:
Answer:
-17
Step-by-step explanation:
it's telling you to replace x with -3.
You have to replace all the x's with -3.
(-3)2 + (-3) - 8 = -17
Answer:
The domain of the function should be:
'x greater than or equal to negative -5'.
Hence, option A is true.
Step-by-step explanation:
Given the expression
The domain of a function is the set of input or arguments for which the function is real and defined
We know that the value, inside the radicand, is the number found inside a radical symbol which must be greater than 0, otherwise, it would make the function undefined,
i.e.
x-5 ≥ 0
x ≥ 5
In other words, the domain of the function should be:
'x greater than or equal to negative -5'.
Therefore, the domain of the function:
x ≥ 5
Hence, option A is true.
