Math help please show work

Problem 1

height of flagpole = meters (SI), feet (imperial)

area of walls = square meters (SI), square feet (imperial)

amount of water = liters (SI), gallons (imperial)

volume of grocery bag = liters (SI), gallons (imperial)

There's not much explanation here. It's simply something you memorize.

Problem 2

1 ft = 12 inches

5 ft = 60 inches multiply both sides by 5

5 ft, 10 in = 60+10 = 70 inches

To convert from inches to cm, we multiply by 2.54 (approx)

70 in = 70*2.54 = 177.8

Shane is roughly 178 cm tall

Problem 3

1 km = 1000 m

0.65 km = 650 m multiply both sides by 0.65

1 m = 100 cm

650 m = 65000 cm ... multiply both sides by 650

We can see that 0.65 km is the same as 65000 cm

Problem 4

1 pound = 16 ounces

Based on this, we divide by 16 to go from ounces to pounds

50 oz = 50/16 = 3.125 pounds

Suppose the length needed to cut off as x
set quadratic equations and use the pythagorean identity (21-x)^2+(42-X) ^2=(45-x)^2
expand and distribute both sides to get quadratic equation x^2-36x+180=0, and find x to be 6cm