398. Ikki noma’lumli birinchi darajali tenglamalar sistemasini yeching:

         1)                                     2)

         3)                                4)

Tenglamalar sistemasini yeching: (399 – 403):

399. 1)                                  2)

         3)                                      4)

400. 1)                                    2)

         3)                                    4)

401. 1)                                       2)

         3)                                               4)

402. 1)                                   2)

         3)                                  4)

403.  1)                                  2)

         3)                                  4)

404.  Ikki sonning yig`indisi 18 ga, ularning ko`paytmasi esa 65 ga teng. Shu sonlarni toping.

405.  Ikki sonning o`rta arifmetigi 20 ga, ularning o`rta geometrigi esa 12 ga teng. Shu sonlarni toping.

406.     Tenglamalar sistemasini yeching:

1)                2)                             3)

407.     Tenglamalar sistemasini yeching:

1)                             2)                             3)

4)                2)                3)

408.     To`g`ri tortburchak shaklidagi maydonni 1 km uzunlikdagi devor bilan o`rab olish kerak. Agar maydonning yuzi 6 ga teng bo`lsa, uning bo`yi va eni qanday bo`lishi kerak?