13.15 ounces of 72% acid and 71.85 ounces of 25% acid are needed
<u>Step-by-step explanation:</u>
Total mass of acid required= 85 ounces
Let the mass of 72% acid be 'a'
Let the mass of 25% acid be 'b'
a + b = 85
b = 85-a
85(40/100) = a(72/100) + b(25/100)
85(2/5) = a(72/100) +(85- a) (25/100)
34 = (72a/100) + (2125/100) - (25a/100)
34 - (2125/100) = (72a + 25a) /100
(3400-2125)/100 = 97a /100
97a = 1275
a = 13.15 ounces
b = 85 - 13.14
b = 71.85 ounces
13.15 ounces of 72% acid and 71.85 ounces of 25% acid are needed
The forth one I can’t type that tho
2xy + 5 - 8 + 3xy - y +7 + 3y = 5xy - 8 + 2y + 12
Sin α = 12/13 opposite/hypothenue
cos α = 5/13 adjacent/hypothenue
tan α = 12/5 opposite/adjacent
