How do I solve #7? do i add all the angles together like a normal triangle and make it equal to 180?

Scarlet bought three pairs of sunglasses and two shirts for $81 and paula bought one pair of sunglasses and five shirts for $105 what is the cost of one pair of sunglasses and one shirt?

F(x)=x/2-2 and g(x)=2x^2+x-3 find (f+g)(x)

Ariel is working at a meat packing plant for 5 nights a week. her regular wage is $11 an hour. she earns tine and a half for any overtime hours. this week she worked 9 hours of over time .how much will ariel earn for overtime this week ?