Math help. explain?

x + (x + 2) + (x + 4) + (x + 6) - 3 = 5x

4x + 12 - 3 = 5x

4x + 9 = 5x

9 = 5x - 4x = x

x=9

x+2=11

x+4=13

x+6=15

9,11,13,15

sue - 8 mph x 1.75 h = 14 miles

Tom - x mph x .25 h = 14 miles, so 14/.25 = 56 mph

x + (x + 2) + (x + 4) = 111

3x + 6 = 111

3x = 105

x = 35

x+2= 37

x+4= 39

x + (x + 2) + (x + 4) = -75

3x + 6 = -75

3x = -81

x = -27

x+2= -29

x+4= -31

1) Because the odd integers are consecutive we know that, if we call the least integer a, then their sum is

a + (a+2) + (a+4) + (a+6).

We are also told that this sum is 3 more than 5a, so we have

4a + 2 + 4 + 6 = 5a + 3

a = 12 - 3

= 9.

The integers are 9, 11, 13 and 15.

2) Tom overtook Sue at 3.45pm (3.30pm plus 15 minutes). In the 1 hour 45 mins since she left camp she's cycled 8mph*(7/4 hours) = 14 miles (1 hour 45 mins = 1 3/4 hour = 7/4 hours). So Tom's average speed is distance travelled/time taken

= 14 miles/(1/4 hour)

= 4*14 miles per hour

= 56 mph.

2a + 1 + 2a + 3 + 2a + 5 + 2a + 7 = 8a + 16

8a + 16 = 5(2a + 1) + 3

I will leave you there ......

How far had Sue travelled by 3.45 ( when Tom overtook)?

Multiply that by 4 - as he had done that in 1/4 hour and you are after his mph ....

the integers are 9, 11, 13, and 15

He was going 48mph