Answer: y = -4/5x - 12
1. First find slope. Since you are trying to find a line perpendicular to y = 5/4x + 10, the slope would be the negative reciprocal of 5/4x.
slope = - 4/5x
2. plug in (-5,-8) and the slope of -4/5 to the point slope form equation
(y-y2) = slope (x-x2)
= y+8=-4/5(x+5)
3. solve and simply y+8=-4/5(x+5)
y = -4/5x - 12 is your answer
Taxi A
1mile £3.50+£1.75=£5.25
Taxi B
1mile £1.25+£2.00=£3.25
Taxi A
2miles £3.50+£3.50=£7.00
Taxi B
2miles £1.25+£4.00=£5.25
Taxi A
3miles £3.50+£5.25=£8.75
Taxi B
3miles £1.25+£6.00=£7.25
Taxi A
4miles £3.50+£7.00=£10.50
Taxi B
4miles £1.25+£8.00=£9.25
Taxi A
5miles £3.50+£8.75=£12.25
Taxi B
5miles £1.25+£10.00=£11.25
Taxi A
6miles £3.50+£10.50=£14.00
Taxi B
6miles £1.25+£12.00=£13.25
Taxi A
7miles £3.50+£12.25=£15.75
Taxi B
7miles £1.25+£14.00=£15.25
Taxi A
8miles £3.50+£14.00=£17.50
Taxi B
8miles £1.25+£16.00=£17.25
Taxi A
9miles £3.50+£15.75=£19.25 (the same)
Taxi B
9miles £1.25+£18.00=£19.25 (the same)
^^^
They would have to drive 9 miles for the taxi to cost the same.
Hope this helped, this is the longest way to work it out but also the simplest.
First I find the individual widget weight
81 - 73 = 2x
8 = 2x
x = 4
Then I find how many widgets were left
73 - 1 = 4y
72 = 4y
18 = y
Y is the amount of widgets left, therefore the amount left is 18
Answer is 430622 as simplified
I think 24 might be the answer if not its 15