1 : 4 = 3 : ( x + 2 ); 2 : x = 7 : 10.

Question

1 : 4 = 3 : ( x + 2 );
2 : x = 7 : 10.

Answer 1

1)х+2=3*4
х+2=12
x=10
2)2х - 7 = х - 10
2х - х = -10 +7
х = -3
________________
2*(-3) - 7 = -3 - 10
-6 - 7 = -3 - 10
-13 = -13 (верно)