She is 3 years older than her brother and has (x+3) in the equation means that x is being used as her brothers age. (She is adding 3 to her brothers age)
The answer is Amy's brother's age.
Answer:
20 +4√2
Step-by-step explanation:
Find the total area the regular pyramid = A + 1/2ps
A is the Base area
p is the perimeter of the base
s is slant height
A = 1/2 * 4 * 4
A = 16/2
A = 8
p = 4 + 4 + (√4^2+4^2)
p = 8 + √32
p = 8 + 4√2
s = 4
Substitute
TSA = 8 + 8 + 4√2 + 4
TSA = 20 +4√2
Hence the total surface area is 20 +4√2
Answer:
Roughly 70.29 degrees
Step-by-step explanation:
Equation:
(2x+27)+(2x-11)+3x = 180
7x + 16 = 180
7x = 164
x ~ 23.43
Angle C:
3x
3（23.43)
70.29
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)
