First we find the common difference...to do this we subtract the first term from the second term. -7 - (-1) = -7 + 1 = -6
now we are going to find the 10th term
an = a1 + (n-1)*d <== formula for finding any term in arithmetic series
a1 = 1st term, d = common difference, n = term we want to find
now we sub
a10 = -1 + (10 -1) * -6
a10 = -1 + (9 * -6)
a10 = -1 - 54
a10 = - 55
now we will find the sum
Sn = (n (a1+ an)) / 2 <== formula for finding the sum
S10 = (10(-1 - 55))/2
S10 = (10(-56) / 2
S10 = -560/2
S10 = - 280
so the sum of the first 10 numbers is -280
Answer:
X=-5
Step-by-step explanation:
Start by isolating the variable to one side. So from here we would add 68 to both sides. we will be left with -8 1/4x = -6.25x+10. Then add 6,25 to both sides to cancel on and get -2x=10. Divide both sides by -2 to get x=-5
take it and leave it somewhere u will forget about it and move on with ur life lol
