Question

СРОЧНООООО
X(в квадрате)+ax-15=0 если x1=3

Answer 1

${x}^{2} + ax - 15 = 0 \ x_{1} = 3 \ {3}^{2} + a times 3 - 15 = 0 \ 3a + 9 - 15 = 0 \ 3a = 6 \ a = 2 \ \ {x}^{2} + 2x - 15 = 0 \ x_{1} + x_{2} = - 2 \ 3 + x_{2} = - 2 \ x_{2} = - 2 - 3 \ x_{2} = - 5$