Step-by-step explanation:

Answer:
10%
Step-by-step explanation:
first let's write out the problem
0.99 is what percent of 9.90 = 0.99=9.90*x
We need to what c is so we would do the opposite operation of multiplication, division so we get,
0.99/9.90= .1
now we turn .1 into percent and get out answer
0.1= 10%
Answer f
Step-by-step explanation:
Answer:
11 + 2x
Step-by-step explanation:
First you will want to separate like variables, so (6, 5) and then (-2x, 4x)
Then you will use the signs to do the math. You can move everything to help visualize the solution easier.
6+5+4x-2x
6+5 = 11
4x-2x = 2x
Because you cannot add or subtract a variable with a non variable, and both numbers are positive you end up with
11 + 2x