3x + 7 = x
First, subtract 3x from both sides. / Your problem should look like: 7 = x - 3x
Second, simplify x - 3x to -2x. / Your problem should look like: 7 = -2x
Third, divide both sides by -2. / Your problem should look like:

= x
Fourth, simplify

to

/ Your problem should look like:

= x
Fifth, switch sides. / Your problem should look like: x =

Answer as fraction:

Answer as decimal: -3.5
Answer: 16 quarts.
Step-by-step explanation:
1 quart = 1/4 gallon.
4 quarts = 1 gallon.
If you have 4 gallons, then you need to multiply 4 by 4, because every gallon is equal to 4 quarts.
4 x 4 = 16.
Therfore, there are 16 quarts in 4 gallons.
Step-by-step explanation:
When the denominator is zero, the expression is undefined
2x-4=0
2x=4
x=2
Assuming that the probability of boys and girls is equal (in reality slightly more boys than girls are born), the probability is 1/2, simply because the older girl's gender is given and therefore not a part of the probability.
This question comes from the 'boy or girl paradox', a.k.a. the Mrs Smith Problem.
Answer:
Step-by-step explanation:
Given that in order to efficiently bid on a contract, a contractor wants to be 95% confident that his error is less than two hours in estimating the average time it takes to install tile flooring.
Std deviation =4.5 errors
95% confidence interval = Mean±1.96*std dev
Hence we have

Sample size should be 20.