4d + 5i = 57
i = 2d - 11
4d + 5(2d - 11) = 57
4d + 10d - 55 = 57
14d = 57 + 55
14d = 112
d = 112/14
d = 8 <== Daphne's age
i = 2d - 11
i = 2(8) - 11
i = 16 - 11
i = 5 <==Isaac's age
#1. x = - (2y) / (1-y)
#2. x = (-4y-3)/(1-y)
I can't really see the other questions, so I only did the first two. Hope this helps!
I believe the answer is range
