9514 1404 393
Answer:
Step-by-step explanation:
Let x represent the amount invested at 13%. Then (3x+199) is the amount invested at 12%. The total interest earned in 1 year is ...
(13%)(x) +(12%)(3x+199) = 1561.50
0.49x +23.88 = 1561.50 . . . . simplify
0.49x = 1537.62 . . . . . . . . . . subtract 23.88
x = 3138 . . . . . . . . . . . . . . . . divide by 0.49
3x+199 = 9613
$3138 was invested at 13%; $9613 was invested at 12%.
4t=r
a=pir^2
sub 4t for r
a=pi(4t)^2
a=pi16t^2
a(t)=16pi(t^2)
A. a(t)=16pi(t^2)
B. sub 4 for t
a(4)=16pi4^2
a(4)=16pi16
a(4)=16*16*3.14
a(4)=803.84 square units
A. a(t)=16pi(t^2)
B. 803.84 square units
Is this a year 9 question and if yes I do not have a clue lol