Answer:
Step-by-step explanation:
let side of cube=x cm
volume=x³ cm³
again side=(x-3) cm
volume=(x-3)³ cm³
x³-(x-3)³=1385
(a³-b³)=(a-b)(a²+ab+b²)
(x-x+3){x²+x(x-3)+(x-3)²}=1385
3(x^2+x²-3x+x²-6x+9)=1385
3(3x²-9x+9)=1385
9x²-27x+27=1385
9x²-27x+27-1385=0
9x²-27x-1358=0
Answer:
33, 77
Step-by-step explanation:
-3. 1 5 9 13 17 21 25 29 33 37 41 45 49 53 57 61 65 69 73 77
Answer:
45000000000
Step-by-step explanation:
when multiplying exponents, you multiply base numbers with no exponent (9 and five in this case) and numbers with exponents (10 in this case). 9 X 5 is 45 and 10 to the power of 7 times 10 to the power of 2 is 10 to the power of 9 or 1000000000. 45 X 1000000000 is 45000000000.
Answer:
Average call Becomes 15 minutes
Step-by-step explanation:
For Tom's Dorm to not run at a loss for switching to the new phone service the Average length of phone calls must not be less than fifteen (15) minutes.
Mathematically,
If he remains on his current phone line, a call of 15 minutes will cost :
= 0.1 * 15 = $1.5
But if he switches to the new phone line and makes a call for 15minutes, the cost will become :
First 2 minutes = 0.6 * 2 = $1.2
Subsequent 13 minutes will cost = 0.02 * 13 = 0.26
Total call for 15minutes on the new phone line = 1.2 + 0.26 = 1.46.
Since the cost became significantly lesser for 15mins when he switches to the new phone line, then the average calls Tom should make should not be less than 15 minutes.
It would be x-2 because you combine like terms
