Assuming you meant her sister used 200 minutes which im still a little unclear of
if everyone in the family used 350 minutes it would add up to 1400, this is the number you want your minutes to add up to
400
350
200 thats 950
subtract 950 from 1400 and you have 450
450 Minutes is your answer
The last one is the correct answer
2x + 1.5x +20 = 90
3.5 x = 90-20
3.5 x = 70
x = 70/3.5
x = 20
angle DAE = 2*20 = 40
angle CAD = 1.5*20 +20 = 50
First of all you subtract 1/8 and 3/8 but you don't subtract the denominator because there are the same number so you only subtract the numerators which are the top ones and btw the answer is 2/8