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
I think that’s the answer
Answer:
Step-by-step explanation:
perimeter of a square = 4 x length (L)
8x - 10 + 8x - 10 = 4L
rearrange the expression
8x + 8x - 10 - 10 = 4L
16x - 20 = 4L
divide both sides for L to stand alone
(16x - 20)/ 4 = 4L/4
(16x - 20)/4 = L
Answer:
Bottom Right. The net for this rectangular prism is Bottom Right.
Answer:
Step-by-step explanation:
T = 5.8t² + 14t + 32 ( 0 ≤ t ≤4 )
a ) when t = 0 ( when car is turned on )
T = 32 ° F .
b ) When t = 2
T = 5.8t² + 14t + 32
= 5.8 x 2² + 14 x 2 + 32
= 23.2 + 28 + 32
= 83.2 ° F
c )
T = 80 ; to find t = ?
80 = 5.8t² + 14t + 32
5.8t² + 14 t - 48 = 0
t = 
t = 1.9 minutes . approx .
