Michelle is 7 years older than her sister Joan, and Joan is 3 years younger than their brother Ryan. If the sum of their ages is 64, how old is Joan? 16
22
18
19

(C) 18

Step-by-step explanation:

We can create a systems of equations. Assuming is Michelle's age, is Joan's age, and is Ryan's age, the equations are:

We can use substitution, since we know the "values" of m and j.

So we know that Joan is 18 years old.

Hope this helped!

find the magnitude of the trig term  

csc

(

x

)

−

1

by taking the absolute value of the coefficient.

1

find the lower bound of the range.

tap for more

y

=

−

2

find the upper bound of the range.

tap for more

y

=

0

the range is  

y

≤

−

2

or  

y

≥

0

.

(

−

∞

,

−

2

]

∪

[

0

,

∞

)

{

y

|

y

≤

−

2

,

y

≥

0

}

step-by-step explanation: