The answer is;
Flame test is a qualitative test".
Flame test is performed for detecting metals in a compound and metals are detected by the color of the flame, and flame color identifies that which metal is this. so this is a qualitative test, different types of metals shows different color of flames.
It works because 7 x 9 x 10 is the same thing as 7 x 90, since 9 x 10 is just 90. So basically he is just writing more but the answer will still be the same.
558,739 is the correct answer.
Answer:
9x
Step-by-step explanation: