Answer:
The call lasted 13 minutes
Step-by-step explanation:
In this question, we are told to find the number of minutes a call lasted.
The initial amount on the card is $30 and after making a phone call just once, the balance went down to $28.83
What was used would be 30 - 28.83 = $1.17 or simply 117 cents
Now these long calls come at a cost of 9 cents per minute and we have a total of 117 cents here; the number of minutes is thus 117/9 = 13
This means Kala spent 13 minutes on the call
x = -2
y = 1
let's multiply second equation by 4 to get a common coefficient of y variable.
16x-8y=-40
add the equations
3×+8y=2
16x-8y=-40
----------------
3x+16x = -38
19x = -38
x = -2
substitute x
3×-2 + 8y = 2
-6 + 8y = 2
8y = 2+6
y = 1
check the answer
-6+8 = 2
-8-2= -20
It is 622 . 622 is 198*3.14
Log(1/216)^(x+2) = log 6^12
(x+2) log(1/216) = log 6^12
xlog(1/216) + 2log(1/216) = log6^12
xlog(1/216) = log6^12 - 2log(1/216)
x = [log6^12-2log(1/216] / log(1/216)
x = -6
