Answer:
x ≈ 1.32, x ≈ - 5.32
Step-by-step explanation:
Given
x² + 4x - 7 = 0 ( add 7 to both sides )
x² + 4x = 7
To complete the square
add ( half the coefficient of the x- term )² to both sides
x² + 2(2)x + 4 = 7 + 4
(x + 2)² = 11 ( take the square root of both sides )
x + 2 = ± 
( subtract 2 from both sides )
x = - 2 ± 
Thus
x = - 2 - ≈ - 5.32 ( to 2 dec. places )
x = - 2 + ≈ 1.32 ( to 2 dec. places )
91.5 is the perimeter. It's just 5a.
Answer: 12.60 per CD
Step-by-step explanation:
Tax 0.80 * 3 = 2.40
40.20 - 2.40 = 37.80
37.8 / 3 = 12.60
Answer:Simplifying
x = -2.125
Step-by-step explanation:Add '-10' to each side of the equation.
10 + -10 + 8x = -7 + -10
Combine like terms: 10 + -10 = 0
0 + 8x = -7 + -10
8x = -7 + -10
Combine like terms: -7 + -10 = -17
8x = -17
Divide each side by '8'.
x = -2.125
Simplifying
x = -2.125
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