Question

Find the number a for which x = 3 is a solution of the given equation.

x+ 7a = 47+ ax - 7a

Answer 1

a=4

Explanation:

`x+7a=47+ax-7a\\\\x+7a-7a=47+ax-7a-7a\\\\x=47+ax-14a\\\\x-47=47+ax-14a-47\\\\x-47=ax-14a\\\\x-47=a(x-14)\\\\(x-47)*(1)/(x-14) =a(x-14)*(1)/(x-14) \\\\(x-47)/(x-14) =a\\\\((3)-47)/((3)-14) =a\\\\(-44)/(-11)=a\\\\a=4`

Answer 2

a=4

Explanation:

x+ 7a = 47+ ax - 7a

Substitute x=3 in the equation

3+7a=47+3a-7a

Combine like terms

7a+7a-3a=47-3=44

11a=44

a=44/11=4