Can anyone help me with this. It asks to solve and check your answer.

[tex]\sf 4m-21=3(5m-1)[/tex]

First, distribute 3 into the parenthesis(multiply it to every term inside):

[tex]\sf 4m-21=15m-3[/tex]

Add 21 to both sides:

[tex]\sf 4m=15m+18[/tex]

Subtract 15m to both sides:

[tex]\sf -11m=18[/tex]

Divide -11 to both sides:

[tex]\sf m=-\dfrac{18}{11}[/tex]

To check our work we can plug this back into the original equation for 'm':

[tex]\sf 4m-21=3(5m-1)[/tex]

[tex]\sf 4(-\dfrac{18}{11})-21=3(5(-\dfrac{18}{11})-1)[/tex]

Multiply:

[tex]\sf -\dfrac{72}{11}-21=3(-\dfrac{90}{11}-1)[/tex]

Distribute 3 into the parenthesis:

[tex]\sf -\dfrac{72}{11}-21=-\dfrac{270}{11}-3[/tex]

Subtract:

[tex]\sf -\dfrac{303}{11}=-\dfrac{303}{11}~\checkmark[/tex]

Both sides are equal to each other, so we solved it correctly.