Answer:
x = ±6
Step-by-step explanation:
x^2/4=9
Multiply by 4 on each side
x^2/4 *4=9*4
x^2 = 36
Take the square root of each side
sqrt(x^2) = ±sqrt(36)
x = ±6
With amounts measured in gallons, let
x = amount of 65% antifreeze
y = amount of 90% antifreeze
1 gal of the 65% brand contains 0.65 gal of pure antifreeze; x gal would contain 0.65x gal. Similarly, y gal of the 90% brand contains 0.90y gal of pure antifreeze.
To obtain 120 gal of 80% antifreeze solution (which contains 0.80•120 = 96 gal of pure antifreeze), we must have
x + y = 120 … … … … … [total volume of antifreeze solution]
0.65x + 0.90y = 96 … [total volume of pure antifreeze]
Solve the first equation for y :
y = 120 - x
Substitute this into the second equation and solve for x :
0.65x + 0.90 (120 - x) = 96
0.65x + 108 - 0.90x = 96
0.25x = 12
x = 48
Solve for y :
y = 120 - 48
y = 72
Well, product means multiply so we need to multiply these fractions.
2 4
--- x --- =
3 5
now, when you are multipliying fractions you multiply the top and the bottom with the other one.
so 2 times 4 and 3 times 5
and you get
8
--
15
since this fraction can not be simplifyed this is the final answer 8/15
B) 5.4 feet because 32 /2 = 16 and 16 /3=5.4 or 5 & 1/5th
