Answer:
2 * x^10 * y^12
Step-by-step explanation:
when dividing by exponents with the same base, you subtract the exponent.
Answer:
x=0.5 and y=5
Step-by-step explanation:
8x+7y=39...eqn(1)×-14
4x-14y=-68...eqn(2)×7
we now have,
-112x-98y=-546
-(28x-98y=-476)
-140x÷-140 =-70÷-140
x=0.5
to solve for y, we substitute (x=0.5) into eqn (1) or eqn 2 which ever you want...
so I'm using eqn 1.
8x+7y=39
8(0.5)+7y=39
7y=39-4
7y÷7=35÷7
y=5
therefore, x=0.5, y=5
proof: substitute both x and y values to get you the same answer as the original solutions in both equations.
we have,
8(0.5)+7(5)=39
4(0.5)-14(5)=-68
Answer:
C. 2.0 < t < 2.5
Step-by-step explanation:
time = distance / speed
The circumference of the lake is given by ...
C = πd = 2π miles ≈ 6.28 miles
Then Johanna's time is ...
(6.28 mi)/(3 mi/h) ≈ 2.09 h
This time is in the interval (2, 2.5), so matches choice C.
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<em>Alternate solution</em>
If we take pi to be 3, then this boils down to ...
2×3/3 = 2 . . . hours
Pi is on the order of 5% more than 3, so her time will be on the order of 5% more than 2 hours, or just above 2, but not as great as 2.5 hours. This sort of estimating can get you to the correct answer without a calculator.
Answer:

Step-by-step explanation: