jim: is your dinner ready at 3?
ann: no, usually dinner ready later.
jim: do you always have fish for dinner?
ann: at our table there is always seafood, but it is not always the fish. my family loves seafood, they are very useful.
jim: do you always begin your dinner at 5 ?
ann: yes, in this time my dad comes back from work, and we содимся dinner with the whole family.
jim: does your sister like to eat fish for lunch?
ann: yes, i think so.
jim: does your father bring ice cream every day?
ann: yes, my sister and i are very fond of ice cream.
jim: your silly cat doesn"t like ice cream, does he?
ann: it's strange, but my cat hates ice-cream
Объяснение:
Объяснение:
Нужно решить полное квадратное уравнение 2x2 + 5x - 7 = 0.
И насколько нам известно мы должны вспомнить и вычислить дискриминант первым действием.
D = b2 - 4ac;
Начнем с того, что выпишем коэффициенты уравнения:
a = 2; b = 5; c = -7;
Вычисляем дискриминант:
D = 52 - 4 * 2 * (-7) = 25 + 56 = 81;
Корни уравнения мы ищем по следующим формулам:
x1 = (-b + √D)/2a = (-5 + √81)/4 = (-5 + 9)/4 = 4/4 = 1;
x2 = (-b - √D)/2a = (-5 - √81)/4 = (-5 - 9)/4 = -14/4 = -3,5;
ответ: x = 1 и x = -3,5 корни уравнения
