Question

persegi panjang memiliki panjang (7×-3) dan lebar (×+2) jika keliling nya 78cm tentukan luas!​

Answer 1

Jawaban:

[tex]p = (7x - 3) \\ l = (x + 2) \\ \\ k = 78 \\ 2(p + l) = 78 \\ 2((7x - 3) + (x + 2)) = 78 \\ 2(7x - 3 + x + 2) = 78 \\ 2(8x - 1) = 78 \\ 16x - 2 = 78 \\ 16x = 78 + 2 \\ 16x = 80 \\ x = \frac{80}{16 } \\ x = 5 \\ mk \\ p = 7x - 3 = 7(5) - 3 = 35 - 3 = 32 \\ l = x + 2 = 5 + 2 = 7 \\ jd \\ luas \: = p \times l = 32 \times 7 = {224cm}^{2} [/tex]