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)
Step-by-step explanation:
In triangles BAD and BCD ,
BD=BD (common)
angle BDA= angle BCD {90°each(given)}
AD=DC (given)
.•. traingle BAD is congruent to triangle BCD (SAS criterion)
Hence , angle A = angle C (CPCT)
For the 1st one we need to solve x. x-y=2 step1: x-y+y=2+y answer: x=y+2