Question

реши уравнения 39:(x•4-25)=13, 40-720:(y+34)=32.

Answer 1

1)
39:(x*4-25)=13 
39:(4x-25)=13
$\frac{39}{4x-25}=13$  (*4x-25)

39=13(3x-25)
3=4x-25
-4x=-25-3
-4x=-28
x=7
2)

$40- \frac{720}{y+34}=32 \\ \\ - \frac{720}{y+34}=-8 (*-(y+34)) \\ \\ 720=(y+34)*8 \\ \\ 720=8y+272 \\ \\ -8y=272-720 \\ \\ \ -8y=-448 \\ \\ y=56$

Answer 2

X•4-25=39:13
Х•4-25=3
Х•4=25+3
Х•4=28
Х=28:4
Х=7
39:(х•4-25)