I hope I am reading the problem right: The price of a mountain bike increased by 20% in the past year. The value is $150. What was the value of the mountain bike last year?
Let's simplify this. One year, there was this radical mountain bike that used to have an unsaid price, <em>x. </em>That year, that price of x increased by 20% more than it was before, or <em>120% times the original value</em>. Because of that, it's now $150.
We can equation this.
1.20x = 150
x = 150/1.2
x = 125
The bike, I believe, cost $125 last year. Hope this helps!
1. Cross multiply
35x = 5(11)
35x = 55
Divide both sides by 35
x = 55/35
x = 11/7
2. (x - 2)/x = 3/8
Cross multiply
3x = 8(x - 2)
3x = 8x - 16
Subtract 8x from both sides
-5x = -16
divide both sides by -5
x = -16/-5
x = 16/5 OR 3 1/5
3. (a + 1)/(a - 1) = 5/6
cross multiply
6(a + 1) = 5(a - 1)
distribute
6a + 6 = 5a - 5
subtract 5a from both sides
a + 6 = -5
subtract 6 from both sides
a = -11
4. (1/3)x - 4 = (2/3)x + 6
multiply each term by 3 to clear the fractions
x - 12 = 2x + 18
subtract x from both sides
-12 = x + 18
subtract 18 from both sides
-30 = x
(8.4 / 6) + 3.2
Hope this helps :)
