Answer:
x = - 7, x = 1
Step-by-step explanation:
Given
x² + 6x = 7
To complete the square
add ( half the coefficient of the x- term )² to both sides
x² + 2(3)x + 9 = 7 + 9
(x + 3)² = 16 ( take the square root of both sides )
x + 3 = ± = ± 4 ( subtract 3 from both sides )
x = - 3 ± 4
x = - 3 - 4 = - 7
x = - 3 + 4 = 1
Solution set = { - 7, 1 }
Answer:
8 pounds of peanuts, 6 pounds of raisins and 6 pounds of chocolate chips
Step-by-step explanation:
Let x be the number of pounds of peanuts and y be the number of pounds of raisins and chocolate chips.
Peanuts cost $2 per pound, then x pounds cost $2x.
Raisins cost $2.50 per pound, then y pounds cost $2.50y.
Chocolate chips cost $4 per pound, then y pounds cost $4y.
In total, x+y+y=20 and those 20 pounds cost
2x+2.50y+4y=20·2.75.
Solve the system of two equations:
From the first equation:
Substitute x into the second equation: