Calculate: (3+3x)/(7)+(3-x)/(5)=(4)/(35)

Expression: $\frac{ 3+3x }{ 7 }+\frac{ 3-x }{ 5 }=\frac{ 4 }{ 35 }$

Multiply both sides of the equation by $35$

$5\left( 3+3x \right)+7\left( 3-x \right)=4$

Distribute $5$ through the parentheses

$15+15x+7\left( 3-x \right)=4$

Distribute $7$ through the parentheses

$15+15x+21-7x=4$

Add the numbers

$36+15x-7x=4$

Collect like terms

$36+8x=4$

Move the constant to the right-hand side and change its sign

$8x=4-36$

Calculate the difference

$8x=-32$

Divide both sides of the equation by $8$

$x=-4$