He buys three cups of hot choclate cause 1.50*3= 4.50
and he buys 5 cups of coffe cause 2.25*5=11.25
and 11.25 + 4.50=15.75
Answer:
Step-by-step explanation:
Given the explicit function as
f(n) = 15n+4
The first term of the sequence is at when n= 1
f(1) = 15(1)+4
f(1) = 19
a = 19
Common difference d = f(2)-f(1)
f(2) = 15(2)+4
f(2) = 34
d = 34-19
d = 15
Sum of nth term of an AP = n/2{2a+(n-1)d}
S20 = 20/2{2(19)+(20-1)15)
S20 = 10(38+19(15))
S20 = 10(38+285)
S20 = 10(323)
S20 = 3230.
Sum of the 20th term is 3230
For the explicit function
f(n) = 4n+15
f(1) = 4(1)+15
f(1) = 19
a = 19
Common difference d = f(2)-f(1)
f(2) = 4(2)+15
f(2) = 23
d = 23-19
d = 4
Sum of nth term of an AP = n/2{2a+(n-1)d}
S20 = 20/2{2(19)+(20-1)4)
S20 = 10(38+19(4))
S20 = 10(38+76)
S20 = 10(114)
S20 = 1140
Sum of the 20th terms is 1140
Answer:
4+3i
Step-by-step explanation:
the 
needs to be simplified
first, I broke it down to
and 
simplifies to i ;and can be broken down to 
and
can be simplified further to 3
Now all you have to do is put it together
4(which you didnt have to do anything to)+ 3i( 3 from the sqrt of 9 and i from the sqrt of -1) sqrt 3( which cant be simplified further)
Answer:
28.95
Step-by-step explanation:
Let x be the number of mm of pure alcohol to be added:
I will add the mm to express the volume in mm
100mm.(19%) + (100%).x mL = (100 mL+x mL).(40%).
Now right again without the %
100.(0.19) + x.(1) = (100+x).(0.4)
19 + x = = 40 + 04x
x - 0.4x = 40 - 19
0.6 x = 21
x = 21/0.6 and x = 35 mL. This te quantity of pure alcohol should to be added to get a solution at 40%.
