Answer:

Step-by-step explanation:
Given,
, solve for x.
Multiply both sides by 2


Add x to both sides


Answer:
4:20
Step-by-step explanation:
because there are 20 teachers in all and 4 science teachers so your chances of getting a science teacher are 4 out of 20
The expression to go with the words is 2x6-9
8 1-and-a-half blocks would be 12 blocks, and so 12/17, because 12 blocks in 17 mins., so you divide 12 by 17 to get ---- blocks per minute, which is 12/17 as a fraction, or approx. 0.705882353 blocks per minute.