1.(45×4) +45=180+45=225
2.45+4=49
3.45×2=90
4.45×3+4=135+4=139
5.(45×4) -45=180-45=135
6.45×4=180
7.45+2=47
8.45×3=135
4lg2-lg(x+1)=lg(2x)-lg(x-1,5);
x+1>0; 2x>0; x-1,5>0;
x>1; x>0; x>1,5;
xє(1.5; +00)
lg2^4 -lg(x+1)=lg(2x/(x-1,5));
lg(16/(x+1)=lg(2x/(x-1,5));
16/(x+1)=2x/(x-1,5);
8/(x+1)=x/(x-1,5);
8(x-1,5)=x(x+1);
8x-12=x^2+x;
x^2+x-8x+12=0;
x^2-7x+12=0;
x1+x2=7; x1*x2=12
x1=3; x2=4
Ответ: 3, 4
1) 9b+6b-15=615
15b=630
b=42
2) 2a+132a+97=472
134a=375
a=2.8 примерно
1) (x-23): 26=8
(x-23) =8*26
(x-23) =208
x=231
2) 1728÷(56-x) =36
56-x=1728÷36
56-x=48
x=8