Question

21(2-x)+12x=44 please need help with check too

Answer 1

Given the expression

`21(2-x)+12x=44`

To find the value of x.

Open the bracket

`\begin{gathered} 21(2-x)+12x=44 \\ 42-21x+12x=44 \\ 42-9x=44 \end{gathered}`

Collect like terms

`\begin{gathered} 42-9x=44 \\ -9x=44-42 \\ -9x=2 \\ \text{Divide both sides by -9} \\ (-9x)/(-9)=(2)/(-9) \\ x=-(2)/(9) \end{gathered}`

Hence, the value of x is -2/9

To check,

Substitute the value of x into the given expression,

If both sides are equal, then the value of x is correct.

Substitute -2/9 for x into the expression given

`\begin{gathered} 21(2-x)+12x=44 \\ 21(2-(-(2)/(9)))+12(-(2)/(9))=44 \\ 21(2+(2)/(9))-(8)/(3)=44 \\ 21((18+2)/(9))-(8)/(3)=44 \\ 21((20)/(9))-(8)/(3)=44 \\ (140)/(3)-(8)/(3)=44 \\ (140-8)/(2)=44 \\ (132)/(3)=44 \\ 44=44 \\ \text{RHS}=\text{LHS} \\ Thus\text{ x}=-(2)/(9) \end{gathered}`

Since the right handside is equal to the left handside, i.e 44 = 44,

Hence, the value of x is -2/9