draw a square with side length of 4. all four angles are 90 degrees and all four sides are 4.
then draw a rectangle with length of 9 and with of 2. all four angles would be 90 degrees, but the proportion of the 2 sides are different when compared to the sides of the square.
there are 15 - 3000lb cars and 3 - 5000lb cars.
we can solve a problem with two variables by setting up a system of equations based on the information given in the problem.
since we know that there are 18 cars total, our first equation is:
a + b = 15, where a = the amount of 3000lb cars and b = the amount of 5000lb cars.
we also know that the total weight of the cars is 30 tons, or 60,000lbs. so, the second equation is:
3000a + 5000b = 60,000
using our first equation to solve for 'b', we get b = 15 - a. we can then substitute this expression in for 'b' in the second equation:
3000a + 5000(18 - a) = 60,000
distribute and combine like terms: 3000a + 90,000 - 5000a = 60,000 or 90,000 - 2000a = 60,000
subtract 90,000 from both sides and divide by -2000 gives us a = 15.
15 + b = 18, so b = 3.
write the equations in word form:
(2x8) – (3x3)
(2 x 50) x2