2/8 = x/(20)

解答

\frac{2}{8} = \frac{x}{20}

x = 5

求解步骤

\frac{2}{8} = \frac{x}{20}

交换两边

\frac{x}{20} = \frac{2}{8}

在两边乘以

10

\frac{x}{2} = \frac{5}{2}

在两边乘以

2

x = 5

23 x - 3 = 3 x + 7

so l v e f or y, x + 4 y = 8

x^{2} - 20 x + m = (x - n)^{2}

lo g_{7} (2401) = x

4 k + 3 = \frac{1}{4} (8 k + 16)