f(x) = x² - 3
f(0) = 0² - 3 = - 3
f(- 1) = (- 1)² - 3 = 1 - 3 = - 2
f(0) - f(- 1) = - 3 - (- 2) = - 3 + 2 = - 1
Ответ : - 1
120x-3y=48x+3
26x-26y=25
72x-3y=3
26x-26y=25
(2a-5)²+a(20-5a)=4a^2+25+20a-5a^2=-a^2+20a+25=5a(-a+9)
Т.к. а=-2/5, то
5*(-2/5)*(2/5+9)=-9,4