Trên hình vẽ bên, có bao nhiêu hình thoi?

a) \(45 - x = 22 + 9\)

\(45 - x = 31\)

\(x = 45 - 31\)

\(x = 14\)

Vậy \(x = 14\)

b) \(84 + \left( {2x - 3} \right) = 129\)

\(2x - 3 = 45\)

\(2x = 48\)

\(x = 24\)

Vậy \(x = 24\)

c) \(27:{3^x} + 31 = {2.5^2} - {4^2}\)

\(27:{3^x} + 31 = 50 - 16\)

\(27:{3^x} = 34 - 31\)

\[27:{3^x} = 3\]

\({3^x} = 9 = {3^2}\)

\(x = 2\)

Vậy \(x = 2\).

a) \(78 - 12.5 + {3^2} = 78 - 60 + 9 = 18 + 9 = 27\)

b) \({4^2}.55 + 2.45.8 - {2022^0} = 16.55 + 16.45 - 1 = 16.100 - 1 = 1599\)

c) \(1800:\left\{ {49 + \left[ {2.{{\left( {{6^2} - 34} \right)}^3} - {5^4}:{5^3}} \right]} \right\}\)

 \( = 1800:\left\{ {49 + \left[ {{{2.2}^3} - 5} \right]} \right\}\)

\( = 1800:\left\{ {49 + \left[ {2.8 - 5} \right]} \right\}\)

\( = 1800:\left\{ {49 + 11} \right\}\)

\( = 1800:60\)

\( = 30\)