c*x-10sqrt(x)+21=0

解答

c \cdot x - 10 x + 21 = 0

x = \frac{- 21 c + 50 + 10 - 21 c + 25}{c ^{2}} {0 < c \leq \frac{25}{21}}, x = \frac{- 21 c + 50 - 10 - 21 c + 25}{c ^{2}} {c < 0 or 0 < c \leq \frac{25}{21}}

求解步骤

c x - 10 x + 21 = 0

去除平方根

100 x = c^{2} x^{2} + 42 c x + 441

解

100 x = c^{2} x^{2} + 42 c x + 441 : x = \frac{- 21 c + 50 + 10 - 21 c + 25}{c ^{2}}, x = \frac{- 21 c + 50 - 10 - 21 c + 25}{c ^{2}}

x = \frac{- 21 c + 50 + 10 - 21 c + 25}{c ^{2}}, x = \frac{- 21 c + 50 - 10 - 21 c + 25}{c ^{2}}

验证解:

x = \frac{- 21 c + 50 + 10 - 21 c + 25}{c ^{2}} {0 < c \leq \frac{25}{21}}, x = \frac{- 21 c + 50 - 10 - 21 c + 25}{c ^{2}} {c < 0 or 0 < c \leq \frac{25}{21}}

解为

x = \frac{- 21 c + 50 + 10 - 21 c + 25}{c ^{2}} {0 < c \leq \frac{25}{21}}, x = \frac{- 21 c + 50 - 10 - 21 c + 25}{c ^{2}} {c < 0 or 0 < c \leq \frac{25}{21}}

x^{\frac{2}{3}} + 2 x^{\frac{1}{3}} - 8 = 0

\frac{- ( 2 x + 1 )}{3 + 2} = 0

x = 0.25

so l v e f or x, z = x (x^{2} + y^{2})^{\frac{1}{2}}

5 x - 6 = - 1