<u>Direct Variation:</u> 
when y = 7: 
14 = 15x
<u>Inverse variation:</u> y*x = k
15 * 2 = k
30 = k
when y = 7: 7 * x = 30
The value of <em>d</em> is 7.5.
The key to solving equations is doing the inverse, or opposite, function/process.
For example, you subtract when d + 1 = 2:
d + 1 = 2
(d + 1) -1 = (2) - 1
d = 1
In the same way, you add values when you have a negative:
5.5 = -2 + d = d - 2
5.5 = d - 2
(5.5) + 2 = (d - 2) + 2
7.5 = d
Now if instead of adding 2, you subtract 2, the problem becomes:
5.5 = d - 2
(5.5) - 2 = (d - 2) - 2
3.5 = d - 4
This doesn't solve your problem, it just makes the value needed to be canceled out larger.
Thus d = 7.5 and you will add because the value is negative.
Answer:
a). -5.7 meters or 5.7 meters below sea level
b). When we combine the two depths we sum them since they are an increment in the same direction and we sum them from the seal level, our first reference point.
Step-by-step explanation:
a). Final depth=Initial depth+deeper increment=(-1.5)+(-4.2)=-5.7
Initial depth=-1.5 represented by a negative number since she is below sea level, meaning her reference point(point 0) is the sea level. The more she moves below the sea level the deeper she goes and the more her depth becomes negative
Deeper increment=-4.1, she further moves deeper from her initial depth(-1.5) by a value of -4.1. In order to find her final depth, we have to sum all the depths she covered from her first reference point which is the see level.
The expression is;
Final depth=Initial depth+deeper increment=(-1.5)+(-4.2)=-5.7 meters
Her final depth=-5.7 meters
b). When we combine the two depths we sum them since they are an increment in the same direction and we sum them from the seal level, our first reference point.
