Tan 32=9/x
x=14.4
cos29=x/7
x=6.12
Right now the dirt bike is worth $500. Next year it will be worth 15% less, or 85% of the current value (because currently it's at 100%, so you would subtract the 15%). To find 85% of the dirt bike's value, you would take $500 and multiply by 85% (or 0.85). This would give you $425 after 1 year. You'd take $425 and multiply that by 85% for the next year, and continue until you reached 5 years of the value decreasing. Does this help?
The answer is y=-4/7x+7. You simply substitute in the given numbers. -4/7 for the slope (m) and 7 for the y-intercept (b).
The gradient formula is (y2-y1)/(x2-x1) aka rise/run, where by (x1,y1) and (x2,y2) are two points on the line.
In this case, the gradient
= -5-(-2))/(2-(-2))
= -3/4
