Answer:
Probably 128 km/h, but maybe 98.5 km/h. See below.
Step-by-step explanation:
What does "at the same time" mean?
If it means that he covered the 240 km in the same time as he convered the 80 km, then this is how you solve it:
80 km in 1.25 hour
240 km in 1.25 hour
Total distance: 80 km + 240 km = 320 km
Total time: 1.25 hour + 1.25 hour = 2.5 hour
average speed = (total distance)/(total time) = 320 km / 2.5 hour = 128 km/h
If it means he covered the 240 km in the same time he covered the 80 km plus the rest, then this is how you solve it:
80 km in 1.25 hour
240 km in 1.25 hour + 45 min = 240 km in 1.25 houir + 0.75 hour = 240 km in 2 hour
Total distance: 80 km + 240 km = 320 km
Total time: 1.25 hour + 2 hour = 3.25 hour
average speed = (total distance)/(total time) = 320 km / 3.25 hour = 98.5 km/h
3x+15^2+10= -2
3x+225+10= -2
3x+235= -2
Divide both sides by 3
x+235=0.67
Subtract 235 from both sides
x= -234.33
Sorry, in advance, if I did it wrong.
1a) Firstly, lets start by expanding the brackets. x × x is x². So x(x+1) = x² + x. Then we do the second part. 2 × x = 2x and 2 × 1 = 2. Now we have
x² + 3x + 2.
Now what we do is simplify through quadratic formula. We look at the last digit which is 2. What two numbers multiplies to give you 2? 2 and 1. 2 x 1 = 2 and 2 + 1 = 3. Our second number is 3 so this is the right amount. so now we just put the two factors together. (x + 1)(x+2). This is the answer.
b) I have explained above and so am just gonna write the answers. After expanding we get x² + 2x + 1. We get simplify to
= (x + 1)(x+1)
c) y² + 3y + 4. This cannot be simplified into the format so we leave it like this.
d) = 0.
Have a go at the last ones by yourself, if you still need help, I am available!
Answer:
Simply substract 0.39 from 0.54 = 0.15
Therefore the carpenter is left with 0.5 metre of wood.
