Question

3+4(5х-3)=4х+7
 3(5х-7)-7(4х+5)=х
 2(6х-5)-7(3х-5)=4х-1
-12х+4(х-3)=-8х-12

Answer 1

3+20х-12=4х+7
20х-4х=7-3+12
16х=16
х=1

15х-21-28х-35=х
15х-28х-х=35+21
-14х=56
х=-4

12х-10-21х+35-4х=-1
-13х=-1+10-35
-13х=-26
х=2

-12х+4х-12+8х=-12
-12=-12