Answer:
169 is the answer.
Step-by-step explanation:
I used a calculator.
This formula solve by discriminant (D=b^2-4ac)
Given equation is y=2x+7 and 
Let's simplify the 2nd equation
before we can start graph so that calculation will be easy

multiply both sides by 2 to cancel out fractions

y=2x+7
which is exactly same as the first equatoin so graph of both will be exactly same and solution will be infinitely many solutions.
y=2x+7 has y-intercept 7 so first point will be (0,7). Slope is 2 so rise 2 unit up then 1 right and graph the new point.
Answer:
D)the time (in hours) a 4-year-old spends unsupervised per day
Step-by-step explanation:
Given that 4-year-olds in a certain country average 3 hours a day unsupervised and that most of the unsupervised children live in rural areas, considered safe
X - the time (in hours) a 4-year-old spends unsupervised per day
X is N(3,1.8)

Answer:
y=28/5
Step-by-step explanation:
Okay so for this we can use cross- multiplication. Basically, the product of the numerator of the first number and the denominator of the second is equal to the product of the denominator of the first and the numerator of the second.
What I mean is: 4*7=5*y
so,
28=5y
y=28/5