## Compassionate one year ago What is happening here [ http://prntscr.com/8jajiq ]

1. anonymous

Maths happening yo

2. Compassionate

Wouldn't it be $120x - 3600 \space \space NOT \space \space 120x - 120 \times 30$

3. Compassionate

Logic being: -120 * 30 - 3,600

4. kropot72

@Compassionate If you calculate the value of -120 * 30 when it arises, the final result of the calculation of the value of x does not change.

5. Compassionate

Come again? Put that in idiot terms for me.

6. kropot72

120x - 3600 = 80x 40x = 3600 x = 90

7. kropot72

@Compassionate Are you there?

8. Compassionate

$120x - 3,600 = 80x \space \space \space, \space \space \space 40x = 3,600 \space \space \space , \space \space \space x = 90$

9. Compassionate

Oh, I get it. So, we can solve it by multiplying out regularly, just the tutorial I am doing does it weird and shows the processes. That's what confused me. And since we know x - 30, we just say 90 - 30.

10. Compassionate

Can we do one more?

11. kropot72

12. Compassionate

Train A has a speed 15 mi/hr greater than train B. If train A travels 150 miles in the same time train B travels 120 miles, what are the speeds of the two trains? Here is my logic. Train A = x + 15. $\frac{ 150 }{ x +15} = \frac{120}{x}$

13. Compassionate

150x = 120x + 1,800 30x = 1,800 x = 60 Recalling x + 15 for A's speed, 60 + 15 = 75

14. kropot72

All good.

15. Compassionate

Thanks a lot, man. I don't usually fan people, I only have a handful, maybe 9 -10, but I'll shoot you a fan because you're quite helpful.

16. kropot72

Thank you and you're welcome :)