<span>12+3(8+x)
= 12 + 24 + 3x
= 3x + 36</span>
84/4=21
now take the 2 even numbers below 21 and the 2 even numbers above 21
18 +20 + 22 +24 = 84
the numbers are 18, 20, 22 & 24
The person who explained the answer because you can see how they got the answer or the evidence they used to get the answer
Step-by-step explanation:
Sn= a+[n-1]d
S2= a+[2-1]d
8.5 = a+d _______Equation 1
S5 = a+[5-1]d
13=a+4d ________Equation 2
Subtract Equation 1 from Equation 2
13=a+4d
-
8.5= a+d
________
4.5= 3d
d=1.5
Substituting d=1.5 in equation 1
8.5=a+1.5
a=8.5-1.5
a=7
Sum of terms of an A.P =
Sn= n/2[2a+(n-1)d]
292= n/2[2×7+(n-1)d]
292=n/2[14+(n-1)1.5
292×2=n[14+(n-1)1.5]
584=n[14+1.5n-1.5]
584= 14n+1.5n²-1.5n
584= 1.5n²+12.5n
1.5n²+12.5n-584
1.5n²-24n+36.5n-584
1.5n(n-16)+36.5(n-16)
(1.5n+36.5)(n-16)
**n-16=0
n=16
