Subtract these 2 equations,
5x-5x +3y-y = -4-6
2y = -10
y = -5
-5 is your answer.
Answer:
25p
Step-by-step explanation:
IM NOT SURE IF ITS RIGHT BUT THAT WHAT I THINK. HAVE A NICE DAY!
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
We know that
Applying the Pythagoras Theorem
c=²=a²+b²
where c is the diagonal of the wall
a=12 ft
b=6 ft
c²=12²+6²-----> c²=144+36-----< c²=180-----> c=√180------> c=6√5 ft
the answer is
<span>the exact length of the brace is 6</span>√5 ft