You don’t have to worry about the t subtract 3 and 9
Answer:
x=4
Step-by-step explanation:
You do a^2 x b^2 = c^2
so 5^2 x ? = 10^2
25 x ?= 100
?= 100/25
?= 4
The answer is B, all you have to do is combine like terms 8x+9x and 12+ -3
Answer:
Noah mistakenly added 25 and 7 in denominator instead of subtracting in the third step.
Step-by-step explanation:
Noah had to rationalize the denominator of 
According to him,

Solving the nominator and denominator

Noah did correctly till this point.
In the next step he add 25 and 7 in the denominator, whereas, it should be subtracted.
Hence,
Noah mistakenly added 25 and 7 in denominator instead of subtracting in the third step.