Answer:
y = 3
x = 2
Step-by-step explanation:
-5x + 4y = 2
9x - 4y = 6
Sum both eq.
-5x + 9x = 4x
+4y - 4y = 0
2 + 6 = 8
then:
4x + 0 = 8
4x = 8
x = 8/4
x = 2
from the first eq.
-5x + 4y = 2
-5*2 + 4y = 2
-10 + 4y = 2
4y = 2 + 10
4y = 12
y = 12/4
y = 3
Check:
from the second eq.
9x - 4y = 6
9*2 - 4*3 = 6
18 - 12 = 6
Answer:
120 liters of 60% alcohol solution is needed
Step-by-step explanation:
Let's assume
x liters of 60% alcohol solution is added
so, we get solution as


we are given
40 liters of a 20% alcohol solution is



so, total alcohol solution is

now, we can find total solutions
total solutions is

now, it is making 50% solution
so, we get

now, we can solve for x




So,
120 liters of 60% alcohol solution is needed
The answer to your question is Y
Nickels is 0,05 of dolar - n
dimes is 0,1 o dolar -d
quarters is 0,25 of dolar -q
dimes =2nickels
d=2n
quarters=2dimes
q=2d=4n
12,5=n(0,05)+2n(0,1)+4n(0,25)
12,5=0,05n+0,2n+n
12,5=1,25n
n=10
q=4n=40
There are 40 quarters