There is a bag with only red marbles and blue marbles. The probability of randomly choosing a red marble is 67. There are 30 red marbles in the bag and each is equally likely to be chosen. Work out how many marbles in total there must be.

answer: i guess 5 units?

step-by-step explanation:

the polynomial is a perfect square trinomial of the form a^2-2ab+b^2:

option a. true

step-by-step explanation:

9x^2-12x+4

comparing with the form a^2-2ab+b^2

1.) a^2=9x^2

solving for a: square root both sides of the equation:

sqrt(a^2)=sqrt(9x^2)

a=sqrt(9) sqrt(x^2)

a=3x

2.) b^2=4

solving for b: square root both sides of the equation:

sqrt(b^2)=sqrt(4)

b=2

to be a perfet square trinomial 2ab must be equal to 12x. let's check:

2ab = 2 (3x) (2)

2ab = 12x

correct

they charge the same amount at 20 minutes.

step-by-step explanation: