Lets call x the amount of 18% solution and y the amount of 40% solution, and write as equations the info of the problem:
18x + 40y = 10(20)
x + y = 10
lets multiply the second equation by -18 and add to the first:
18x + 40y = 200
-18x -<span> 18y = -180
</span>----------------------
0 + 22y = 20
y = 20/22 = 10/11
and substitute in the original equation:
x <span>+ y = 10
</span>x = 10 - y
x = 10 - 10/11
x = 110/11 - 10/11
x = 100/11
so they have to use 100/11 liters of 18% solution and 10/11 liters of 40% solution
Answer:
x = 24 , y = 19
Step-by-step explanation:
The opposite sides of a parallelogram are congruent , then
2x - 8 = x + 16 ( subtract x from both sides )
x - 8 = 16 ( add 8 to both sides )
x = 24
and
2y = y + 19 ( subtract y from both sides )
y = 19
3r-6=-21
3r-6+6=-21+6 (Add 6 to both sides...)
3r=-15
r=-5
3r-6=21
3r-6+6=21+6 (Add 6 to both sides...)
3r=27
r=9
r=-5 or r=9
<span>B) 2 3/4 , 2.34, 9/4 hope this helps
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