561 x 103 = 57783, so the place value of the 1 will be 3. :)
Steps:
216 mm3 is the volume.
Given the volume, you can take the cube root of the volume to find the side.
The cube root of 216 is 6.
Answer: 6
Both variables (x) are 3.
4×3=12
12-2=10
16×3=48
48-8=40
3 fits the variable of the missing number.
7a + 6c + 9a - 15c
-- Look for all the 'a's 7a, 9a
-- Addum up 16a
-- Look for all the 'c's 6c, -15c
-- Addum up -9c
-- Write the results 16a - 9c
