Answer:
Answer: x is 15
Step-by-step explanation:
[tex]{ \tt{6x - 12 = 78}}[/tex]
» Apply the addition rule of equality by adding 12 on either sides:
[tex]{ \tt{(6x - 12) + { \green{12}} = 78 + { \green{12}}}} \\ { \tt{6x = 90}}[/tex]
» Apply the division rule of equality by dividing either sides by 6
[tex]{ \tt{ \frac{6x}{{ \blue{6}}} = \frac{90}{{ \blue{6}}} }} \\ \\ { \tt{x = \frac{90}{6} }} \\ \\ { \underline{ \tt{ \: \: x = 15 \: \: }}}[/tex]
• Checking the solution :
[tex]{ \tt{6x - 12 = 78}}[/tex]
» Substitute x with its value (15) in the equation:
[tex]{ \tt{6(15) - 12 = 78}} \\ { \tt{90 - 12 = 78}} \\ { \boxed{ \tt{ \: 78 = 78 \: }}}[/tex]
• Since the left hand side is equal to the right hand side, the value of x is consistent.
