Answer:
21
Step-by-step explanation:
We know that the sqaure root of 121 = 11.
So, A - 10 = 11
=> A = 21
The equivalent expression is b)
The second one
Step-by-step explanation:
You just have to plug the numbers they give you into the equation. For the first one, you have 0 + 5y = 10; 5y = 10; y = 2. For the second one, x + 5(0) = 10; x + 0 = 10; x = 10. And lastly, for the third one, x + 5(6) = 10; x + 30 = 10; x = -20.
Answer:

Step-by-step explanation:
move the decimal so there is one non-zero digit to the left of the decimal point. the number of decimal places you move will be the exponent on the 10. if the decimal is being moved to the right, the exponent will be negative. if the decimal is being moved to the left, the exponent will be positive.