Question

me podrían ayudar a resolver estas ecuaciones con su comprobación ​

Answer 1

$\frac{4x}{8} + 9 = 18 \\ \frac{4x}{8} = 18 - 9 \\ \frac{4x}{8} = 9 \\ 8 \times \frac{4x}{8} = 8 \times 9 \\ 4x = 72 \\ x = \frac{72}{4} \\x = 18 \\ \\ \\ \\ Comprobación: \\ \frac{4 \times 18}{8} + 9 = 18 \\ \frac{72}{8} + 9 = 18 \\ 9 + 9 = 18 \\ 18 = 18$

$\frac{2x}{8} + 5 = 15 \\ \frac{2x}{8} = 15 - 5 \\ \frac{2x}{8} = 10 \\ 8 \times \frac{2x}{8} = 10 \times 8 \\ 2x = 80 \\ x = 40 \\ \\ \\ \\ Comprobación: \\ \frac{2 \times 40}{8} + 5 = 15 \\ \frac{80}{8} + 5 = 15 \\ 10 + 5 = 15 \\ 15 = 15$

$\frac{2x}{8} - 5 = 15 \\ \frac{2x}{8} = 15 + 5 \\ \frac{2x}{8} = 20 \\ 8 \times \frac{2x}{8} = 8 \times 20 \\ 2x = 160 \\ x = 80 \\ \\ \\ \\ \\ Comprobación: \\ \frac{2 \times 80}{8} - 5 = 15 \\ \frac{160}{8} - 5 = 15 \\ 20- 5 = 15 \\ 15 = 15$

$\frac{3x}{9} + 12 = 28 \\ \frac{3x}{9} = 28 - 12 \\ \frac{3x}{9} = 16 \\ 9 \times \frac{3x}{9} = 16 \times 9 \\ 3x = 144 \\ x = 48 \\ \\ \\ \\ \\ Comprobación: \\ \frac{3 \times 48}{9} + 12 = 28 \\ \frac{144}{9} + 12 = 28 \\ 16 + 12 = 28 \\ 28 = 28$