48) a) 2/3:4/5=(2*5)/(4*3)=10/12 верно
б) 3/7:4/9=(3*9)/(4*7)=27:28 верно
58) а)14/15=3/x 15/14=x/3 x=15*3/14=45/14
б) 12/29=1/(58*x) 29/12=58x x=29/(12*58)=1/24
в) 12/25=7/(15*x) 25/12=15x/7 25*7/12*15=x 35/36=x
г) 144/125=3/2x 125/144=2x/3 125*3/144*2=x x=375/288=125/96=1 29/96
X^2=x/x;
x^2=1;
x=√1;
x=1; x=-1
А)-9,25-0,75= -10
б)-27-5,45= -32,45
в)-5,8-17,75= -23,55
(17y-8y+3)/7=12
(9y+3)/7=12
9y+3=84
9y=81
Y=9