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:
Figure 1 is 50 cm. Figure 2 is 225 mm.
Step-by-step explanation:
The slope of the perpendicular line will be 2. Remember, a perpendicular slope is the negative reciprocal.
So, we can make the equation 
. We need to find b, and put b in.
To find b, put in the numbers of y and x.
Solve for b:
Now replace b in the original equation with 12 and that will be the answer:
The answer is 
.
Answer:
B. all real numbers
Step-by-step explanation:
hope that helps
<span>So we need to explain how we know 21/30 is greater than 2/3. Well lets expand 2/3 by multiplying the numerator and the denumerator by 10. That way we get 20 / 30. Since 21/30 has 1/30 more than 20/30 we can clearly see that 21/30 is greater than 20/30 or 2/3.</span>
