Answer:
[tex]\large \boxed{x = 0.50}[/tex]
Step-by-step explanation:
[tex]\begin{array}{rcll}2(x + 1.25) & = & 3.5 & \\x + 1.25 &= & \dfrac{3.5}{2} & \text{Divided each side by 2}\\\\x + 1.25& = & 1.75 & \text{Simplified}\\x& = & 0.50 & \text{Subtracted 1.25 from each side}\\\end{array}\\\large \boxed{\mathbf{x = 0.50}}[/tex]
Check:
[tex]\begin{array}{rcl}2(0.50 + 1.25) & = & 3.5\\2(1.75) & = & 3.5\\3.50 & = & 3.5\\\end{array}[/tex]
OK.