First, let me do the Mathematical part of that, and then I shall explain the theory behind it.
Mathematical part:
We are going to multiply 513 with 46. So the two partial products that we are going to choose are 40 and 6.
Multiply 513 with 6 first.
513
x46
--------------------------
18 (as 6*3 = 18)
60 (as 6*10 = 60; In 513, the digit at tenths place is 1, so 1*10=10)
3000 (as 6*500 = 3000; In 513, 5 is at hundredth place, so 5*100=500)
120 (as 40*3 = 120; since 4 is at the tenth place, so 4*10=40)
400 (as 40*10 = 400)
20000 (as 40*500 = 20000)
--------------------------
23598 (Add all of them)
Theory:
As you can see above that we have chosen the two partial products individually which are 6 and 40. Since 4 in 46 is in tenth place, we have to consider it 40 (since 4*10 = 40). One by one, we first multiply 6 with 513. Then we move to the tenth place, and multiply 513 with 40. At the end, we have added all the results we found after multiplication.
Check: If we check the multiplication result by using the calculator, we would get the same result (23598).
Another Method (instant):
513 * (40+6) = (513*40) + (513*6) = 23598.
Answer. First option: t > 6.25
Solution:
Height (in feet): h=-16t^2+729
For which interval of time is h less than 104 feet above the ground?
h < 104
Replacing h for -16t^2+729
-16t^2+729 < 104
Solving for h: Subtracting 729 both sides of the inequality:
-16t^2+729-729 < 104-729
-16t^2 < -625
Multiplying the inequality by -1:
(-1)(-16t^2 < -625)
16t^2 > 625
Dividing both sides of the inequality by 16:
16t^2/16 > 625/16
t^2 > 39.0625
Replacing t^2 by [ Absolute value (t) ]^2:
[ Absolute value (t) ]^2 > 39.0625
Square root both sides of the inequality:
sqrt { [ Absolute value (t) ]^2 } > sqrt (39.0625)
Absolute value (t) > 6.25
t < -6.25 or t > 6.25, but t can not be negative, then the solution is:
t > 6.25
Any decimal under 1, i believe.
6. Take your compass and place the pointed edge on point B. Place one point on each side of B, each the same distance away from B. Next, place your compass on one of the two new points and extend your compass to draw a circle. Repeat with the SAME radian from the other point. Find where the two circles intersect with each other and draw a line from the points of intersection to point B. Place point A anywhere on that line that you just created and then you're done!
7. Select any place along either line and place point S on it. Next, using the same method as above, draw two circles with the same radius around both points S and R. Draw a line through the intersection points. Locate the intersection where your new line connects with the line across from the shared line of RS. Place a point at the intersection, for your reference, then connect that point to point S. Now you have completed this problem as well.
8. Use a straight edge to draw one line. Place points A and B on each end. Use the circle method yet again to find a line perpendicular to line AB. Next, take your compass and set it to the distance from point A to B. Use that same distance to make a point on the perpendicular line. This creates point C. The final step is to connect A with C and B with C.
Peggy has 12 practice sessions
The first step is finding the unit rate. We can do this by evaluating
21/1.75 divided by 1.75/1.75.
When you divide the two, you get 12.
To check your work you do 12(1.75) and you will get 21
