Explanation:
3.1.
your question
75x-25=5x+125
collect like terms
70x=150
Divide both side by the coefficient of x
70x/70=150/70
70 ti cancel 70 on x side to leave x alone
:. x=150/70 or 2.14
3.2.
6×(3x-2)=7×(x+3)
multiply by the bracket
18x-12=7x+21
collect like terms
18x+7x=21+12
25x=33
divide by the coefficient of x
25x/25=33/25
x=33/25 or 1.32
3.3.
10/x-3=8
cross multiply(know that 8 is /1)
x‐3×8=10×1
8x-24=10
8x=10+24
8x=34
divide both sides by coefficient of x
8x/8=34/8
8x=34/8 or 4.25
3.4.
x+7=5x-13
collect like terms
7+13=5x-x
20=4x
divide both sides by the coefficient of x
20/4=4x/4
5=x
:.x=5
3.5.
20x+4=4x-46
collect like terms
20x-4x=-46-4
16x=-52
divide both sides by the coefficient of x
16x/16=-52/16
:.x=52/16 or 3.25