Start with parenthesis so that will be 7x -21so then you will get 4x = 7x -21 then you will subtract 7x and 4x and you will get -3x = -21 and your answer is 7 because both numbers are a negative and that will equal a positive.
Answer:
b and c
Step-by-step explanation:
purple is greater than 7/2
The probability of getting exact two tails is 1/4