A^2 - 11^2 = ( a - 11 )( a + 11 ), because we have the formula d<span>ifference of squares, a^2 - b^2 = ( a - b )( a + b );</span>
Recall your d = rt, distance = rate * time.
if, the southbound train is going at a speed of say " r " mph, since we know that the northbound one is going faster by 4 miles, than is really going at " r + 4 " mph then.
now, we know in 2.5 hours, they're 330 miles from each other, thus the southbound train has been rolling for 2.5 hours, and the northbound train has also been rolling for 2.5 hours.
if the northbound train has covered on those 2.5 hours say " d " miles, then the southbound train has covered the slack, or " 330 - d ".

how fast is the northbound going? well, r + 4.
Answer:
Step-by-step explanation:
He wants to estimate the height of the statue of Thomas Jefferson. Corey stands so that his line of vision to the top and base of the statue form a right angle as shown in the diagram. ... So, the total height of the statue is about 159 + 68 or 227 inches, which is equivalent to 18 ft 11 in. ANSWER: 18 ft 11 in.
Answer:
a) enlargement
b) scale factor is 2
Step-by-step explanation:
As we can see, we went from the block to the red figure
a) Since the red figure is bigger, then what we have is an enlargement of the original figure
b) As we can see, the coordinates of the red is two times the value of the coordinates of the black
So, we can conclude that what we have as a scale factor is 2
Answer: Choice D) 
================================================
Work Shown:

Explanation:
First I subtracted y/b from both sides. Then I multiplied both sides by 'a' to fully isolate x. You can optionally distribute the 'a' through to each term inside the parenthesis, but your teacher has chosen not to do this.