Answer:
S = 85cm^2
Step-by-step explanation:
The surface area of a square pyramid is given by the following formula:

where it has taken into account the sum of the area of a square and four triangles:

h: slant height = 6cm
b: base = 5cm
By replacing in the formula you obtain:

hence, the surface area is 85cm^2
Simplify both sides of the equation, add 6x to both sides, subtract 48 from both sides, then divide both sides by 70. Your answer would be x= -1
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:
-64
Step-by-step explanation:
we should put -2 for j and -1 for k,
Step-by-step explanation:
x2^+8x=-20
9x^2=20
x^2=20-9
x^2=11
√x^2=√11
x=√11