Irst thought: since he needs 7 3/4 tons, and each load can carry LESS than a ton, he'll need to make MORE than 7 3/4 loads. So when you get your answer, make sure it it passes that common sense test. Next: He's got to divide the 7 3/4 ton total among all those loads, 3/4 ton at a time. So he needs to divide: 7 3/4 divided by 3/4. It will be easier to do the math if we turn 7 3/4 into an improper fraction, which will be 31/4. So we have to divide 31/4 divided by 3/4, which will give us 10, with 1/4 left over, for a total of 10 1/4 loads. BUT: the wording is that each load carries AT MOST 3/4 ton, so he may carry less than that amount in any given load(s). So he needs to do an amount GREATER THAN OR EQUAL TO 10 3/4 loads. For practical purposes, that means he has to fill his truck (at least part way) 11 different times. (Think of it as completely filled the first 10 times, and 3/4 filled on the 11th/final time.)
Describe um it’s a line and has a F
Because of the relatively large coefficients {9, 42, 49}, applying the quadratic formula would be a bit messy. Instead, I've chosen to "complete the square:"
9x^2 + 42x + 49 = 0 can be re-written as 9 [ x^2 + (42/9)x ] = -49
Dividing both sides by 9, we get [ x^2 + (42/9)x ] = - 49/9
Completing the square: [ x^2 + (42/9)x + (21/9)^2 - (21/9)^2 ] = -49/9
[ x + 21/9 ]^2 = 441/81 - 441/81 = 0
Then [ x + 21/9 ] = 0, and x = -21/9 (this is a double root).
