Answer:
x²(9x– 11)(9x + 11)
Step-by-step explanation:
81x⁴ – 121x²
The expression can be factorised as follow:
81x⁴ – 121x²
x² is common to both term. Thus:
81x⁴ – 121x² = x²(81x² – 121)
Recall:
81 = 9²
121 = 11²
Therefore,
x²(81x² – 121) = x²(9²x² – 11²)
= x²[(9x)² – 11²]
Difference of two squares
x²(9x– 11)(9x + 11)
Therefore,
81x⁴ – 121x² = x²(9x– 11)(9x + 11)
Answer:
6 mph
Step-by-step explanation:
Speed = Distance/Time. Distance is 18, time is 3. So 18/3, or 6.
Hope this helps!
Answer:
18617.66 ft^2
Step-by-step explanation:
sides of triangular base
a= 145ft ,
b = 257ft ,
c = 290ft
<u>calculate the area of the base </u>
The base is a scalene triangle hence the area is calculated as follows
s = ( a + b + c ) / 2
= ( 145 + 257 + 290 ) / 2 = 346
Area of triangle = 
= 18617.66 ft^2
