Step-by-step explanation:


Note that


Therefore,

Answer:
I believe the answer is 12.57
Step-by-step explanation:
I'm going to assume you meant crayon instead of can:
First step is to find how many boxes she/he has left.
30 - 10 = 20
So the teacher has 20 boxes left;
Now, knowing that each box has 16 crayons, then we simply multiply the 20 by 16 to find the total number of crayons left over:
20 x 16 = 320
So the art teacher has 320 crayons left over.
Hope this helps!
Answer:
step 1: move the -4 to the right: x^2 -2x = 4
step 2: add 1 to each side: x^2 -2x + 1 = 4 + 1
step 3: factor the left side and simplify the right side: (x-1)^2 = 5
step 4: take the square root of each side: x - 1 = sqr root of 5
step 5: move the 1 to the other side:
and 
9.9=9×9=81 and you have to multiply