Obliczmy x
[tex]4x - 1 + 3x + 1 + 2x + 1 + x + 1 = 42 \\ 10x = 42 - 2 \\ 10x = 40 | \div 10 \\ x = 4[/tex]
Zatem podstawa ma
[tex]2x + 1 + x + 1 \\ 2 \times 4 + 1 + 4 + 1 = \\ = 8 + 6 = \\ = 14[/tex]
Pole
[tex] \frac{a \times h}{2} = \frac{14 \times 12}{2} = 7 \times 12 = 84[/tex]
