Question

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

Answer 1

$\sf 4m-21=3(5m-1)$

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

$\sf 4m-21=15m-3$

Add 21 to both sides:

$\sf 4m=15m+18$

Subtract 15m to both sides:

$\sf -11m=18$

Divide -11 to both sides:

$\sf m=-\dfrac{18}{11}$

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

$\sf 4m-21=3(5m-1)$

$\sf 4(-\dfrac{18}{11})-21=3(5(-\dfrac{18}{11})-1)$

Multiply:

$\sf -\dfrac{72}{11}-21=3(-\dfrac{90}{11}-1)$

Distribute 3 into the parenthesis:

$\sf -\dfrac{72}{11}-21=-\dfrac{270}{11}-3$

Subtract:

$\sf -\dfrac{303}{11}=-\dfrac{303}{11}~\checkmark$

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