X and y are the numbers
y>x
sum (addition) of twice a number (2x) and larger number (y) is (=) 145
2x+y=145
difference between them is 55 (y is bigger so it would be x is subtracted from y)
y-x=55
so the equations are
2x+y=145 and
y-x=55
we could add x to both sides in the 2nd equation to obtain
y=x+55, but that doesn't really represent that the difference is 55, though they are the same euation
so I would say C and D only
The units of the first number are "dollars." The second number has no apparent units, so we'll consider it a "pure number". This means the product will have the units of "dollars."
The two numbers together have 2+1=3 digits to the right of the decimal point(s). This means the final product will have 3 digits to the right of the decimal point. Since one of the factors is "dollars," it seems likely the result will need to be rounded to cents (2 decimal places). We'll provide the answer both ways (with 3 and with 2 decimal places.)
With these preliminaries out of the way, we have the problem of multiplying
... 79 × 37
There are numerous methods taught for finding this product. In the end, they all amount to multiplying every digit in one number by every digit in the other number and adding the results with appropriate place values. Several methods use 2-dimensional tables or arrays in their process. Here, we will use text on a line.
... 79 × 37 = (70 +9) × (30 +7)
... = 70×30 + 9×30 + 70×7 + 9×7
... = 2100 + 270 +490 + 63
... = 2100 +760 +63
... = 2860 +63
... = 2923
Putting the decimal point 3 places from the right, and adding the dollar sign gives our product:
... $0.79 × 3.7 = $2.923 ≈ $2.92
The answer to your question is 6.67.
