Answer:
30 each of 23% bars and 18 each of 79% bars
Step-by-step explanation:
If x is the number of 1 kg 23% copper bars, and y is the number of 1 kg 79% copper bars, then:
x + y = 48
0.23x + 0.79y = 0.44(48)
Substituting and solving:
0.23x + 0.79(48-x) = 0.44(48)
0.23x + 37.92 - 0.79x = 21.12
16.8 = 0.56x
x = 30
y = 48 - x
y = 18
You need 30 each of 23% bars and 18 each of 79% bars.
Just plus in x for -3
f(x) = 4(-3)^2 + 3(-3) - 11
f (x) = 4(9) -9 - 11
f(x) = 36 - 20
f(x) = 16
X(x + 3) + 34 = (x + 5)(x + 2)
First, expand to remove parentheses.
Second, add '2x + 5x' to get '7x'.
Third, cancel out '

' on both sides.
Fourth, subtract '3x' from both sides.
Fifth, subtract '7x - 3x' to get '4x'.
Sixth, subtract '10' from both sides.
Seventh, subtract '34 - 10' to get '24'.
Eighth, divide both sides by '4', leaving the 'x' by itself.
Ninth, since '24 ÷ 4 = 6', simplify the fraction to '6'.
Tenth, switch your sides to get the answer.

Answer:
x = 6
1/15 as a decimal would be 0.6666666......
Or you can round that off to 0.67
Answer:
4 brothers and 3 sisters
Step-by-step explanation:
Let x be the number of brothers and y be the number of sisters in the family.
1. Each brother has x-1 brothers and y sisters. If each brother has as many sisters as brothers, then

2. Each sister has y-1 sisters and x brothers. If each sister has twice as many brothers as she has sisters, then

3. Solve the system of two equations:

Then
